Observation of a New Particle in the Search for the Standard Model Higgs Boson with the ATLAS Detector at the LHC

The ATLAS Collaboration

This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full impact and signiﬁcance of their contributions to the experiment.

Abstract

A search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented. The datasets used correspond to integrated luminosities of approximately

√√

4.8 fb^⁻¹collected at s = 7 TeV in 2011 and 5.8 fb^⁻¹at s = 8 TeV in 2012. Individual searches in the channels H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνµν in the 8 TeV data are combined with previously published results of searches for H→ ZZ^{⁽^∗⁾}, WW^{⁽^∗⁾}, bb^¯and τ⁺τ⁻in the 7 TeV data and results from improved analyses of the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV is presented. This observation, which has a signiﬁcance of 5.9 standard deviations, corresponding to a background ﬂuctuation probability of 1.7 ×10^⁻⁹, is compatible with the production and decay of the Standard Model Higgs boson.

Observation of a New Particle in the Search for the Standard Model Higgs Boson with the ATLAS Detector at the LHC

The ATLAS Collaboration

This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full impact and signiﬁcance of their contributions to the experiment.

Abstract

A search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented. The datasets used correspond to integrated luminosities of approximately 4.8 fb^⁻¹collected at ^√s = 7 TeV in 2011 and 5.8 fb^⁻¹at ^√s = 8 TeV in 2012. Individual searches in the channels H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνµν in the 8 TeV data are combined with previously published results of searches for H→ ZZ^{⁽^∗⁾}, WW^{⁽^∗⁾}, bb^¯and τ⁺τ⁻in the 7 TeV data and results from improved analyses of the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of

126.0 ± 0.4 (stat) ± 0.4 (sys) GeV is presented. This observation, which has a signiﬁcance of 5.9 standard deviations, corresponding to a background ﬂuctuation probability of 1.7 × 10^⁻⁹, is compatible with the production and decay of the Standard Model Higgs boson.

1. Introduction

The Standard Model (SM) of particle physics [1–4] has been tested by many experiments over the last four decades and has been shown to successfully describe high energy particle interactions. However, the mechanism that breaks electroweak symmetry in the SM has not been veriﬁed experimentally. This mechanism [5– 10], which gives mass to massive elementary particles, implies the existence of a scalar particle, the SM Higgs boson. The search for the Higgs boson, the only elementary particle in the SM that has not yet been observed, is one of the highlights of the Large Hadron Col lider [11] (LHC) physics programme.

Indirect limits on the SM Higgs boson mass of mH < 158 GeV at 95% conﬁdence level (CL) have been set using global ﬁts to precision electroweak results [12]. Direct searches at LEP [13], the Tevatron [14–16] and the LHC [17, 18] have previously excluded, at 95% CL, a SM Higgs boson with mass below 600 GeV, apart from some mass regions between 116 GeV and 127 GeV.

Both the ATLAS and CMS Collaborations reported excesses of events in their 2011 datasets of proton

√

proton (pp) collisions at centre-of-mass energy s = 7 TeV at the LHC, which were compatible with SM Higgs boson production and decay in the mass region 124–126 GeV, with signiﬁcances of 2.9 and 3.1 standard deviations (σ ), respectively [17, 18]. The CDF and DØ experiments at the Tevatron have also recently reported a broad excess in the mass region 120–135 GeV; using the existing LHC constraints, the observed local signiﬁcances for mH = 125 GeV are 2.7 σ for CDF [14], 1.1 σ for DØ [15] and 2.8 σ for their combination [16].

The previous ATLAS searches in 4.6–4.8 fb^⁻¹of data

√

at s = 7 TeV are combined here with new searches for

H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→_√eνµν in the 5.8–5.9 fb^⁻¹of pp collision data taken at s = 8 TeV between April and June 2012. In the H→ WW^{⁽^∗⁾}→ eνµν channel, the kinematic region in which a SM Higgs boson with a mass between 110 GeV and 140 GeV is searched for was kept blinded until satisfactory agreement was found between the observed and predicted number of events in control samples dominated by the principal backgrounds. The analyses of the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels were re-optimised with simulation and frozen before looking at the 8 TeV data.

The data were recorded with instantaneous luminosi

−2

ties up to 6.8 × 10³³cms^⁻¹; they are therefore affected by multiple pp collisions occurring in the same or neighbouring bunch crossings (pile-up). In the 7 TeV

¹The symbol e stands for electron or muon.

data, the average number of interactions per bunch crossing was approximately 10; the average increased to approximately 20 in the 8 TeV data. The reconstruction, identiﬁcation and isolation criteria used for electrons and photons in the 8 TeV data are improved, making the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ analyses more robust against the increased pile-up. In the H→ WW^{⁽^∗⁾}→ eνeν channel, the increased pile-up deteriorates the event missing transverse momentum, E^miss, resolution, which

results in signiﬁcantly larger Drell-Yan background in the same-ﬂavour ﬁnal states. Since the eµ ﬁnal state provides most of the sensitivity of the search, only this ﬁnal state has been used in the analysis of the 8 TeV data.

This letter is organised as follows. The ATLAS de tector is brieﬂy described in Section 2. The simulation samples and the signal predictions are presented in Section 3. The analyses of the H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνµν channels are described in Sec tions 4–6, respectively. The statistical procedure used to analyse the results is summarised in Section 7. The systematic uncertainties which are correlated between datasets and search channels are described in Section 8. The results of the combination of all channels are re ported in Section 9, while Section 10 provides the con clusions.

2. The ATLAS detector

The ATLAS detector [19–21] is a multipurpose parti cle physics apparatus with forward-backward symmetric cylindrical geometry. The inner tracking detector (ID) consists of a silicon pixel detector, a silicon microstrip detector (SCT), and a straw-tube transition radiation tracker (TRT). The ID is surrounded by a thin superconducting solenoid which provides a 2 T magnetic ﬁeld, and by high-granularity liquid-argon (LAr) sampling electromagnetic calorimetry. The electromagnetic calorimeter is divided into a central barrel (pseudorapidity^²|η| < 1.475) and end-cap regions on either end of the detector (1.375 < |η| < 2.5 for the outer wheel and 2.5 < |η| < 3.2 for the inner wheel). In the region matched to the ID (|η| < 2.5), it is radially segmented

²ATLAS uses a right-handed coordinate system with its origin at the nominal interaction point (IP) in the centre of the detector, and the z-axis along the beam line. The x-axis points from the IP to the centre of the LHC ring, and the y-axis points upwards. Cylindrical coordinates (r,φ) are used in the transverse plane, φ being the azimuthal angle around the beam line. Observables labeled “transverse” are projected into the x − y plane. The pseudorapidity is deﬁned in terms of the polar angle θ as η = − ln tan(θ/2).

into three layers. The ﬁrst layer has a ﬁne segmentation in η to facilitate e/γ separation from π⁰and to improve the resolution of the shower position and direction measurements. In the region |η| < 1.8, the electromagnetic calorimeter is preceded by a presampler detector to correct for upstream energy losses. An iron-scintillator/tile calorimeter gives hadronic coverage in the central rapidity range (|η| < 1.7), while a LAr hadronic end-cap calorimeter provides coverage over 1.5 < |η| < 3.2. The forward regions (3.2 < |η| < 4.9) are instrumented with LAr calorimeters for both electromagnetic and hadronic measurements. The muon spectrometer (MS) surrounds the calorimeters and consists of three large air-core superconducting magnets providing a toroidal ﬁeld, each with eight coils, a system of precision tracking chambers, and fast detectors for triggering. The combination of all these systems provides charged particle measurements together with eﬃcient and precise lepton and photon measurements in the pseudorapidity range |η| < 2.5. Jets and E^missare reconstructed using en-

ergy deposits over the full coverage of the calorimeters, |η| < 4.9.

3. Signal and background simulation samples

The SM Higgs boson production processes considered in this analysis are the dominant gluon fusion (gg → H, denoted ggF), vector-boson fusion

(qq→ qq^'H, denoted VBF) and Higgs-strahlung

(qq→ WH, ZH, denoted WH/ZH). The small contribution from the associated production with a tt pair (qq¯/gg → t¯tH) is taken into account only

tH, denoted t¯in the H→ γγ analysis.

For the ggF process, the signal cross section is computed at up to next-to-next-to-leading order (NNLO) in QCD [22–28]. Next-to-leading order (NLO) elec troweak (EW) corrections are applied [29, 30], as well as QCD soft-gluon re-summations at up to next-to-next to-leading logarithm (NNLL) [31]. These calculations, which are described in Refs. [32–35], assume factori sation between QCD and EW corrections. The transverse momentum, pT, spectrum of the Higgs boson in the ggF process follows the HqT calculation [36], which includes QCD corrections at NLO and QCD soft-gluon re-summations up to NNLL; the eﬀects of ﬁnite quark masses are also taken into account [37].

For the VBF process, full QCD and EW correc tions up to NLO [38–41] and approximate NNLO QCD corrections [42] are used to calculate the cross sec tion. Cross sections of the associated WH/ZH processes (VH) are calculated including QCD corrections up to NNLO [43–45] and EW corrections up to NLO [46].

The cross sections for the t¯

tH process are estimated up to NLO QCD [47–51]. The total cross sections for SM Higgs boson production at the LHC with mH = 125 GeV are predicted to

√√

be 17.5 pb for s = 7 TeV and 22.3 pb for s = 8 TeV [52, 53].

The branching ratios of the SM Higgs boson as a function of mH, as well as their uncertainties, are calcu lated using the HDECAY [54] and PROPHECY4F [55, 56 ] programs and are taken from Refs. [52, 53]. The interference in the H→ ZZ^{⁽^∗⁾}→ 4e ﬁnal states with iden tical leptons is taken into account [53, 55, 56].

Table 1: Event generators used to model the signal and background processes. “PYTHIA” indicates that PYTHIA6 and PYTHIA8 are

√√

used for simulations of s = 7 TeV and s = 8 TeV data, respectively.

Process Generator

ggF, VBF POWHEG [57, 58] +PYTHIA WH, ZH, t¯PYTHIA

W+jets, Z/γ^∗+jets ALPGEN [59] +HERWIG

tt, tW, tb MC@NLO [60] +HERWIG

tqb AcerMC [61] +PYTHIA

qq¯→ WW MC@NLO+HERWIG

gg → WW gg2WW [62] +HERWIG

qq¯→ ZZ POWHEG [63] +PYTHIA

gg → ZZ gg2ZZ [64] +HERWIG

WZ MadGraph+PYTHIA, HERWIG

Wγ+jets ALPGEN+HERWIG

Wγ^∗ [65] MadGraph+PYTHIA

qq¯/gg → γγ SHERPA

The event generators used to model signal and background processes in samples of Monte Carlo (MC) sim ulated events are listed in Table 1. The normalisations of the generated samples are obtained from the state of the art calculations described above. Several diﬀerent programs are used to generate the hard-scattering processes. To generate parton showers and their hadroni sation, and to simulate the underlying event [66–68], PYTHIA6 [69] (for 7 TeV samples and 8 TeV sam ples produced with MadGraph [70, 71] or AcerMC) or PYTHIA8 [72] (for other 8 TeV samples) are used. Al ternatively, HERWIG [73] or SHERPA [74] are used to generate and hadronise parton showers, with the HERWIG underlying event simulation performed using JIMMY [75]. When PYTHIA6 or HERWIG are used, TAUOLA [76] and PHOTOS [77] are employed to de scribe tau lepton decays and additional photon radiation from charged leptons, respectively.

The following parton distribution function (PDF) sets are used: CT10 [78] for the POWHEG, MC@NLO, SHERPA, gg2WW and gg2ZZ samples; CTEQ6L1 [79] for the ALPGEN, MadGraph and HERWIG samples; and MRSTMCal [80] for the PYTHIA6, PYTHIA8 and AcerMC samples.

Acceptances and eﬃciencies are obtained mostly from full simulations of the ATLAS detector [81] us ing Geant 4 [82]. These simulations include a realistic modelling of the pile-up conditions observed in the data. Corrections obtained from measurements in data are applied to account for small diﬀerences between data and simulation (e.g. large samples of W, Z and J/ψ decays are used to compare lepton reconstruction and identiﬁcation eﬃciencies).

4. H → ZZ^{⁽^∗)}→ 4t channel

The search for the SM Higgs boson through the decay H → ZZ^{⁽^∗⁾}→ 4e, where e = e or µ, provides good sensitivity over a wide mass range (110600 GeV), largely due to the excellent momentum resolution of the ATLAS detector. This analysis searches for Higgs boson candidates by selecting two pairs of isolated leptons, each of which is comprised of two leptons with the same ﬂavour and opposite charge. The expected cross section times branching ratio for the process H → ZZ^{⁽^∗⁾}→ 4e with mH = 125 GeV is 2.2 fb for

√√

s = 7 TeV and 2.8 fb for s = 8 TeV.

The largest background comes from continuum (Z^{⁽^∗⁾}/γ^∗)(Z^{⁽^∗⁾}/γ^∗) production, referred to hereafter as ZZ^{⁽^∗⁾}. For low masses there are also important background contributions from Z + jets and tt¯production, where charged lepton candidates arise either from decays of hadrons with b-or c-quark content or from misidentiﬁcation of jets.

The 7 TeV data have been re-analysed and combined with the 8 TeV data. The analysis is improved in several aspects with respect to Ref. [83] to enhance the sensitiv ity to a low-mass Higgs boson. In particular, the kinematic selections are revised, and the 8 TeV data analysis beneﬁts from improvements in the electron reconstruction and identiﬁcation. The expected signal signiﬁcances for a Higgs boson with mH = 125 GeV are

1.6 σ for the 7 TeV data (to be compared with 1.25 σ in Ref. [83]) and 2.1 σ for the 8 TeV data.

4.1. Event selection

The data are selected using single-lepton or dilepton triggers. For the single-muon trigger, the pT threshold is 18 GeV for the 7 TeV data and 24 GeV for the 8 TeV data, while for the single-electron trigger the transverse energy, ET, threshold varies from 20 GeV to 22 GeV for the 7 TeV data and is 24 GeV for the 8 TeV data. For the dielectron triggers, the thresholds are 12 GeV for both electrons. For the dimuon triggers, the thresholds for the 7 TeV data are 10 GeV for each muon, while for the 8 TeV data the thresholds are 13 GeV. An additional asymmetric dimuon trigger is used in the 8 TeV data with thresholds 18 GeV and 8 GeV for the leading and sub-leading muon, respectively.

Muon candidates are formed by matching reconstructed ID tracks with either a complete track or a track-segment reconstructed in the MS [84]. The muon acceptance is extended with respect to Ref. [83] us ing tracks reconstructed in the forward region of the MS (2.5 < |η| < 2.7), which is outside the ID coverage. If both an ID and a complete MS track are present, the two independent momentum measurements are combined; otherwise the information of the ID or the MS is used alone. Electron candidates must have a well-reconstructed ID track pointing to an electromagnetic calorimeter cluster and the cluster should satisfy a set of identiﬁcation criteria [85] that require the lon gitudinal and transverse shower proﬁles to be consistent with those expected for electromagnetic showers. Tracks associated with electromagnetic clusters are ﬁt ted using a Gaussian-Sum Filter [86], which allows for bremsstrahlung energy losses to be taken into account.

Each electron (muon) must satisfy pT > 7 GeV (pT > 6 GeV) and be measured in the pseudorapidity range |η| < 2.47 (|η| < 2.7). All possible quadruplet combinations with same-ﬂavour opposite-charge lepton pairs are then formed. The most energetic lepton in the quadruplet must satisfy pT > 20 GeV, and the second (third) lepton in pT order must satisfy pT > 15 GeV (pT > 10 GeV). At least one of the leptons must satisfy the single-lepton trigger or one pair must satisfy the dilepton trigger requirements. The leptons are required to be separated from each other by ΔR =

(Δη)²+ (Δφ)²> 0.1 if they are of the same ﬂavour and by ΔR > 0.2 otherwise. The longitudinal impact parameters of the leptons along the beam axis are required to be within 10 mm of the reconstructed primary vertex. The primary vertex used for the event is deﬁned as the

reconstructed vertex with the highestp²of associated

tracks and is required to have at least three tracks with pT > 0.4 GeV. To reject cosmic rays, muon tracks are required to have a transverse impact parameter, deﬁned as the distance of closest approach to the primary vertex in the transverse plane, of less than 1 mm.

The same-ﬂavour and opposite-charge lepton pair with an invariant mass closest to the Z boson mass (mZ ) in the quadruplet is referred to as the leading lepton pair. Its invariant mass, denoted by m12, is required to be between 50 GeV and 106 GeV. The remaining same-ﬂavour, opposite-charge lepton pair is the sub-leading lepton pair. Its invariant mass, m34, is required to be in the range mmin < m34 < 115 GeV, where the value of mmin depends on the reconstructed four-lepton invariant mass, m4e. The value of mmin varies monotonically from 17.5 GeV at m4e = 120 GeV to 50 GeV for m4e> 190 GeV [87]. All possible lepton pairs in the quadruplet that have the same ﬂavour and opposite charge must satisfy mee > 5 GeV in order to reject backgrounds involving the production and decay of J/ψ mesons. If two or more quadruplets satisfy the above selection, the one with the highest value of m34 is selected. Four diﬀerent analysis sub-channels, 4e,2e2µ, 2µ2e and 4µ, arranged by the ﬂavour of the leading lepton pair, are deﬁned.

Non-prompt leptons from heavy ﬂavour decays, electrons from photon conversions and jets mis-identiﬁed as electrons have broader transverse impact parameter distributions than prompt leptons from Z boson decays and/or are non-isolated. Thus, the Z+jets and tt¯background contributions are reduced by applying a cut on the transverse impact parameter signiﬁcance, deﬁned as the transverse impact parameter divided by its uncertainty, d0/σd₀. This is required to be less than 3.5 (6.5) for muons (electrons). The electron impact parameter is aﬀected by bremsstrahlung and thus has a broader distribution.

In addition, leptons must satisfy isolation requirements based on tracking and calorimetric information. The normalised track isolation discriminant is deﬁned as the sum of the transverse momenta of tracks inside a cone of size ΔR = 0.2 around the lepton direction, excluding the lepton track, divided by the lepton pT. The tracks considered in the sum are those compatible with the lepton vertex and have pT > 0.4 GeV (pT > 1 GeV) in the case of electron (muon) candidates. Each lepton is required to have a normalised track isolation smaller than 0.15. The normalised calorimetric isolation for electrons is computed as the sum of the ET of positive- energy topological clusters [88] with a reconstructed barycentre falling within a cone of size ΔR = 0.2 around the candidate electron cluster, divided by the electron ET. The summed energy of the cells assigned to the electron cluster is excluded, while a correction is applied to account for the electron energy deposited outside the cluster. The algorithm for topological clustering suppresses noise by keeping cells with a signiﬁcant energy deposit and their neighbours. The ambient energy deposition in the event from pile-up and the underlying event is accounted for using a calculation of the median transverse energy density from low-pT jets [89, 90]. The normalised calorimetric isolation for electrons is required to be less than 0.20. The normalised calorimetric isolation discriminant for muons is deﬁned by the ratio to the pT of the muon of the ET sum of the calorimeter cells inside a cone of size ΔR = 0.2 around the muon direction minus the energy deposited by the muon. Muons are required to have a normalised calorimetric isolation less than 0.30 (0.15 for muons without an associated ID track). For both the track-and calorimeter-based isolation, any contributions arising from other leptons of the quadruplet are subtracted.

The combined signal reconstruction and selection efﬁciencies for a SM Higgs with mH = 125 GeV for the 7 TeV (8 TeV) data are 37% (36%) for the 4µ channel, 20% (22%) for the 2e2µ/2µ2e channels and 15% (20%) for the 4e channel.

The 4e invariant mass resolution is improved by applying a Z-mass constrained kinematic ﬁt to the leading lepton pair for m4e< 190 GeV and to both lepton pairs for higher masses. The expected width of the reconstructed mass distribution is dominated by the experimental resolution for mH < 350 GeV, and by the natural width of the Higgs boson for higher masses (30 GeV at mH = 400 GeV). The typical mass resolutions for mH = 125 GeV are 1.7 GeV, 1.7 GeV/2.2 GeV and

2.3 GeV for the 4µ,2e2µ/2µ2e and 4e sub-channels, respectively.

4.2. Background estimation

The expected background yield and composition are estimated using the MC simulation normalised to the theoretical cross section for ZZ^{⁽^∗⁾}production and by methods using control regions from data for the Z + jets and tt¯processes. Since the background composition depends on the ﬂavour of the sub-leading lepton pair, different approaches are taken for the ee+µµ and the ee+ee ﬁnal states. The transfer factors needed to extrapolate the background yields from the control regions deﬁned below to the signal region are obtained from the MC simulation. The MC description of the selection eﬃciencies for the diﬀerent background components has been veriﬁed with data.

The reducible ee + µµ background is dominated by tt¯and Z + jets (mostly Zbb^¯) events. A control region is deﬁned by removing the isolation requirement on the leptons in the sub-leading pair, and by requiring that at least one of the sub-leading muons fails the transverse impact parameter signiﬁcance selection. These modiﬁcations remove ZZ^{⁽^∗⁾}contributions, and allow both the tt¯and Z + jets backgrounds to be estimated simultaneously using a ﬁt to the m12 distribution. The tt¯background contribution is cross-checked by selecting a control sample of events with an opposite charge eµ pair with an invariant mass between 50 GeV and 106 GeV, accompanied by an opposite-charge muon pair. Events with a Z candidate decaying to a pair of electrons or muons in the aforementioned mass range are excluded. Isolation and transverse impact parameter signiﬁcance requirements are applied only to the leptons of the eµ pair.

In order to estimate the reducible ee + ee background, a control region is formed by relaxing the selection criteria for the electrons of the sub-leading pair. The diﬀerent sources of electron background are then separated into categories consisting of non-prompt leptons from heavy ﬂavour decays, electrons from photon conversions and jets mis-identiﬁed as electrons, using appro priate discriminating variables [91]. This method allows the sum of the Z + jets and tt¯background contributions to be estimated. As a cross-check, the same method is also applied to a similar control region containing same-charge sub-leading electron pairs. An additional crosscheck of the ee + ee background estimation is performed by using a control region with same-charge sub-leading electron pairs, where the three highest pT leptons satisfy all the analysis criteria whereas the selection cuts are relaxed for the remaining electrons. All the cross-checks yield consistent results.

Table 2: Summary of the estimated numbers of Z + jets and tt¯back

√√

ground events, for the s = 7 TeV and s = 8 TeV data in the entire phase-space of the analysis after the kinematic selections described in the text. The backgrounds are combined for the 2µ2e and 4e channels, as discussed in the text. The ﬁrst uncertainty is statistical, while the second is systematic.

Background Estimated numbers of events

√√

s = 7 TeV s = 8 TeV

4µ

Z+jets 0.3± 0.1 ±0.1 0.5± 0.1 ±0.2 tt¯0.02±0.02±0.01 0.04±0.02±0.02

2e2µ

Z+jets 0.2± 0.1 ±0.1 0.4± 0.1 ±0.1 tt¯0.02±0.01±0.01 0.04±0.01±0.01

2µ2e

Z+jets, t¯t	2.6± 0.4 ±0.4		4.9± 0.8 ±0.7
		4e
Z+jets, t¯t	3.1± 0.6 ±0.5		3.9± 0.7 ±0.8

The data-driven background estimates are sum marised in Table 2. The distribution of m34, for events selected by the analysis except that the isolation and transverse impact parameter requirements for the sub leading lepton pair are removed, is presented in Fig. 1.

Figure 1: Invariant mass distribution of the sub-leading lepton pair (m34) for a sample deﬁned by the presence of a Z boson candidate and an additional same-ﬂavour electron or muon pair, for the combination

√√

of s = 7 TeV and s = 8 TeV data in the entire phase-space of the analysis after the kinematic selections described in the text. Isolation and transverse impact parameter signiﬁcance requirements are applied to the leading lepton pair only. The MC is normalised to the data-driven background estimations. The relativelly small contribution of a SM Higgs with mH = 125 GeV in this sample is also shown.

4.3. Systematic uncertainties

The uncertainties on the integrated luminosities are determined to be 1.8% for the 7 TeV data and 3.6% for the 8 TeV data using the techniques described in Ref. [92].

The uncertainties on the lepton reconstruction and identiﬁcation eﬃciencies and on the momentum scale and resolution are determined using samples of W, Z and J/ψ decays [84, 85]. The relative uncertainty on the signal acceptance due to the uncertainty on the muon reconstruction and identiﬁcation eﬃciency is ±0.7% (±0.5%/±0.5%) for the 4µ (2e2µ/2µ2e) channel for m4e = 600 GeV and increases to ±0.9% (±0.8%/±0.5%) for m4e = 115 GeV. Similarly, the relative uncertainty on the signal acceptance due to the uncertainty on the electron reconstruction and identiﬁcation eﬃciency is ±2.6% (±1.7%/±1.8%) for the 4e (2e2µ/2µ2e) channel for m4e = 600 GeV and reaches ±8.0% (±2.3%/±7.6%) for m4e = 115 GeV. The uncertainty on the electron energy scale results in an uncertainty of ±0.7% (±0.5%/±0.2%) on the mass scale of the m4e distribution for the 4e (2e2µ/2µ2e) channel. The impact of the uncertainties on the electron energy resolution and on the muon momentum resolution and scale are found to be negligible.

The theoretical uncertainties associated with the sig nal are described in detail in Section 8. For the SM ZZ^{⁽^∗⁾}background, which is estimated from MC simulation, the uncertainty on the total yield due to the QCD scale uncertainty is ±5%, while the eﬀect of the PDF and αs uncertainties is ±4% (±8%) for processes initi ated by quarks (gluons) [53]. In addition, the dependence of these uncertainties on the four-lepton invariant mass spectrum has been taken into account as discussed in Ref. [53]. Though a small excess of events is ob served for m4l > 180 GeV, the measured ZZ^{⁽^∗⁾}→ 4e cross section [93] is consistent with the SM theoreti cal prediction. The impact of not using the theoretical constraints on the ZZ^{⁽^∗⁾}yield on the search for a Higgs boson with mH < 2mZ has been studied in Ref. [87] and has been found to be negligible . The impact of the interference between a Higgs signal and the non-resonant gg → ZZ^{⁽^∗⁾}background is small and becomes negligible for mH < 2mZ [94].

Figure 2: The distribution of the four-lepton invariant mass, m4e , for the selected candidates, compared to the background expectation in

√

the 80–250 GeV mass range, for the combination of the s = 7 TeV

√

and s = 8 TeV data. The signal expectation for a SM Higgs with mH = 125 GeV is also shown.

4.4. Results The expected distributions of m4e for the background and for a Higgs boson signal with mH = 125 GeV are compared to the data in Fig. 2. The numbers of ob

served and expected events in a window of ±5 GeV around mH = 125 GeV are presented for the combined 7 TeV and 8 TeV data in Table 3. The distribution of the m34 versus m12 invariant mass is shown in Fig. 3. The statistical interpretation of the excess of events near m4e = 125 GeV in Fig. 2 is presented in Section 9.

Table 3: The numbers of expected signal (mH = 125 GeV) and background events, together with the numbers of observed events in the data, in a window of size ±5 GeV around 125 GeV, for the combined

√√

s = 7 TeV and s = 8 TeV data.

Signal ZZ^{⁽^∗⁾}Z + jets, tt¯Observed

4µ	2.09±0.30	1.12±0.05	0.13±0.04	6
2e2µ/2µ2e	2.29± 0.33	0.80±0.05	1.27±0.19	5
4e	0.90±0.14	0.44±0.04	1.09±0.20	2

Figure 3: Distribution of the m34 versus the m12 invariant mass, before the application of the Z-mass constrained kinematic ﬁt, for the selected candidates in the m4e range 120–130 GeV. The expected distributions for a SM Higgs with mH = 125 GeV (the sizes of the boxes indicate the relative density) and for the total background (the intensity of the shading indicates the relative density) are also shown.

5. H→ γγ channel

The search for the SM Higgs boson through the decay H→ γγ is performed in the mass range between 110 GeV and 150 GeV. The dominant background is SM diphoton production (γγ); contributions also come from γ+jet and jet+jet production with one or two jets mis-identiﬁed as photons (γ j and jj) and from the Drell-Yan process. The 7 TeV data have been re-analysed and the results combined with those from the 8 TeV data. Among other changes to the analysis, a new category of events with two jets is introduced, which enhances the sensitivity to the VBF process. Higgs boson events produced by the VBF process have two forward jets, originating from the two scattered quarks, and tend to be devoid of jets in the central region. Overall, the sensitivity of the analysis has been improved by about 20% with respect to that described in Ref. [95].

5.1. Event selection

The data used in this channel are selected using a diphoton trigger [96], which requires two clusters formed from energy depositions in the electromagnetic calorimeter. An ET threshold of 20 GeV is applied to each cluster for the 7 TeV data, while for the 8 TeV data the thresholds are increased to 35 GeV on the leading (the highest ET) cluster and to 25 GeV on the sub-leading (the next-highest ET) cluster. In addition, loose criteria are applied to the shapes of the clusters to match the expectations for electromagnetic showers initiated by photons. The eﬃciency of the trigger is greater than 99% for events passing the ﬁnal event selection.

Events are required to contain at least one reconstructed vertex with at least two associated tracks with pT > 0.4 GeV, as well as two photon candidates. Photon candidates are reconstructed in the ﬁducial region |η| < 2.37, excluding the calorimeter barrel/end-cap transition region 1.37 ≤|η| < 1.52. Photons that convert to electron-positron pairs in the ID material can have one or two reconstructed tracks matched to the clusters in the calorimeter. The photon reconstruction eﬃciency is about 97% for ET > 30 GeV.

In order to account for energy losses upstream of the calorimeter and energy leakage outside of the cluster, MC simulation results are used to calibrate the energies of the photon candidates; there are separate calibrations for unconverted and converted candidates. The calibration is reﬁned by applying η-dependent correction factors, which are of the order of ±1%, determined from measured Z→ e⁺e⁻events. The leading (sub-leading) photon candidate is required to have ET > 40 GeV (30 GeV).

Photon candidates are required to pass identiﬁcation criteria based on shower shapes in the electromagnetic calorimeter and on energy leakage into the hadronic calorimeter [97]. For the 7 TeV data, this information is combined in a neural network, tuned to achieve a similar jet rejection as the cut-based selection described in Ref. [95], but with higher photon e ﬃciency. For the 8 TeV data, cut-based criteria are used to ensure reliable photon performance for recently-recorded data. This cut-based selection has been tuned to be robust against pile-up by relaxing requirements on shower shape criteria more susceptible to pile-up, and tightening others.

The photon identiﬁcation eﬃciencies, averaged over η, range from 85% to above 95% for the ET range under consideration.

To further suppress the jet background, an isolation requirement is applied. The isolation transverse energy is deﬁned as the sum of the transverse energy of positive-energy topological clusters, as described in Section 4, within a cone of size ΔR = 0.4 around the photon candidate, excluding the region within 0.125 ×

0.175 in Δη×Δφ around the photon barycentre. The distributions of the isolation transverse energy in data and simulation have been found to be in good agreement using electrons from Z→ e⁺e⁻events and photons from

Z → ee⁻γ events. Remaining small diﬀerences are taken into account as a systematic uncertainty. Photon candidates are required to have an isolation transverse energy of less than 4 GeV.

5.2. Invariant mass reconstruction

The invariant mass of the two photons is evaluated using the photon energies measured in the calorimeter, the azimuthal angle φ between the photons as determined from the positions of the photons in the calorimeter, and the values of η calculated from the position of the identiﬁed primary vertex and the impact points of the photons in the calorimeter.

The primary vertex of the hard interaction is identiﬁed by combining the following information in a global likelihood: the directions of ﬂight of the photons as determined using the longitudinal segmentation of the electromagnetic calorimeter (calorimeter pointing), the

parameters of the beam spot, and the p_Tof the tracks associated with each reconstructed vertex. In addition, for the 7 TeV data analysis, the reconstructed conversion vertex is used in the likelihood for converted photons with tracks containing hits in the silicon layers of the ID. The calorimeter pointing is suﬃcient to ensure that the contribution of the opening angle between the photons to the mass resolution is negligible. Using the calorimeter pointing alone, the resolution of the vertex z coordinate is ∼ 15 mm, improving to ∼ 6 mm for events with two reconstructed converted photons. The tracking information from the ID improves the identiﬁcation of the vertex of the hard interaction, which is needed for the jet selection in the 2-jet category.

With the selection described in Section 5.1, in the diphoton invariant mass range between 100 GeV and 160 GeV, 23788 and 35251 diphoton candidates are observed in the 7 TeV and 8 TeV data samples, respectively.

Data-driven techniques [98] are used to estimate the numbers of γγ, γ j and jj events in the selected sample. The contribution from the Drell-Yan background is determined from a sample of Z→ e⁺e⁻decays in data where either one or both electrons pass the photon selection. The measured composition of the selected sample is approximately 74%, 22%, 3% and 1% for the γγ, γ j, jj and Drell-Yan processes, respectively, demonstrating the dominance of the irreducible diphoton production. This decomposition is not directly used in the signal search; however, it is used to study the parameterisation of the background modelling.

5.3. Event categorisation

To increase the sensitivity to a Higgs boson signal, the events are separated into ten mutually exclusive categories having diﬀerent mass resolutions and signal-tobackground ratios. An exclusive category of events containing two jets improves the sensitivity to VBF. The other nine categories are deﬁned by the presence or not of converted photons, η of the selected photons, and pTt, the component^³of the diphoton pT that is orthogonal to the axis deﬁned by the diﬀerence between the two pho ton momenta [99, 100].

Jets are reconstructed [101] using the anti- kt algo rithm [102] with radius parameter R = 0.4. At least two jets with |η| < 4.5 and pT > 25 GeV are required in the 2-jet selection. In the analysis of the 8 TeV data, the pT threshold is raised to 30 GeV for jets with

2.5 < |η| < 4.5. For jets in the ID acceptance (|η| < 2.5), the fraction of the sum of the pT of tracks, associated with the jet and matched to the selected primary vertex, with respect to the sum of the pT of tracks associated with the jet (jet vertex fraction, JVF) is required to be at least 0.75. This requirement on the JVF reduces the number of jets from proton-proton interactions not associated with the primary vertex. Motivated by the VBF topology, three additional cuts are applied in the 2-jet selection: the diﬀerence of the pseudorapidity between the leading and sub-leading jets (tag jets) is required to be larger than 2.8, the invariant mass of the tag jets has to be larger than 400 GeV, and the azimuthal angle difference between the diphoton system and the system of the tag jets has to be larger than 2.6. About 70% of the signal events in the 2-jet category come from the VBF process.

The other nine categories are deﬁned as follows: events with two unconverted photons are separated into unconverted central (|η| < 0.75 for both candidates) and unconverted rest (all other events), events with at least

γ2 γ2 γ2 γ1

³pTt = (p ^γ¹+ p ) × (p ^γ¹− p ) / p ^γ¹− p , where p and p ^γ²

TTTTTTT T

are the transverse momenta of the two photons.

Table 4: Number of events in the data (ND) and expected number of signal events (NS) for mH = 126.5 GeV from the H→ γγ analysis, for each category in the mass range 100−160 GeV. The mass resolution FWHM (see text) is also given for the 8 TeVdata. The Higgs boson production cross section multiplied by the branching ratio into two photons (σ×B(H → γγ)) is listed for mH = 126.5 GeV. The statistical uncertainties on NS and FWHM are less than 1 %.

√

s	7 TeV		8 TeV
σ × B(H → γγ) [fb]	39		50	FWHM [GeV]
Category	ND NS	ND	NS	FWHM [GeV]
Unconv. central, low pTt Unconv. central, high pTt Unconv. rest, low pTt Unconv. rest, high pTt Conv. central, low pTt Conv. central, high pTt Conv. rest, low pTt Conv. rest, high pTt Conv. transition 2-jet	2054 10.5 97 1.5 7129 21.6 444 2.8 1493 6.7 77 1.0 8313 21.1 501 2.7 3591 9.5 89 2.2	2945 173 12136 785 2015 113 11099 706 5140 139	14.2 2.5 30.9 5.2 8.9 1.6 26.9 4.5 12.8 3.0	3.4 3.2 3.7 3.6 3.9 3.5 4.5 3.9 6.1 3.7
All categories (inclusive)	23788 79.6	35251	110.5	3.9

one converted photon are separated into converted central (|η| < 0.75 for both candidates), converted transition (at least one photon with 1.3 < |η| < 1.75) and converted rest (all other events). Except for the converted transition category, each category is further divided by a cut at pTt= 60 GeV into two categories, low pTt and high pTt. MC studies show that signal events, particularly those produced via VBF or associated production (WH/ZH and t¯

tH), have on average larger pTt than background events. The number of data events in each category, as well as the sum of all the categories, which is denoted inclusive , are given in Table 4.

5.4. Signal modelling

The description of the Higgs boson signal is obtained from MC, as described in Section 3. The cross sections multiplied by the branching ratio into two photons are given in Table 4 for mH = 126.5 GeV. The number of signal events produced via the ggF process is rescaled to take into account the expected destructive interference between the gg → γγ continuum background and ggF [103], leading to a reduction of the production rate by 2−5% depending on mH and the event category. For both the 7 TeV and 8 TeV MC samples, the fractions of ggF, VBF, WH, ZH and t¯

tH production are approximately 88%, 7%, 3%, 2% and 0.5%, respectively, for mH = 126.5 GeV.

In the simulation, the shower shape distributions are shifted slightly to improve the agreement with the data [97], and the photon energy resolution is broad ened (by approximately 1% in the barrel calorimeter and 1.2−2.1% in the end-cap regions) to account for small diﬀerences observed between Z→ e⁺e⁻data and MC events. The signal yields expected for the 7 TeV and 8 TeV data samples are given in Table 4. The over all selection eﬃciency is about 40%.

The shape of the invariant mass of the signal in each category is modelled by the sum of a Crystal Ball func tion [104], describing the core of the distribution with a width σCB, and a Gaussian contribution describing the tails (amounting to <10%) of the mass distribution. The expected full-width-at-half-maximum (FWHM) is

3.9 GeV and σCB is 1.6 GeV for the inclusive sample. The resolution varies with event category (see Table 4); the FWHM is typically a factor 2.3 larger than σCB.

5.5. Background modelling

The background in each category is estimated from data by ﬁtting the diphoton mass spectrum in the mass range 100−160 GeV with a selected model with free parameters of shape and normalisation. Diﬀerent models are chosen for the diﬀerent categories to achieve a good compromise between limiting the size of a potential bias while retaining good statistical power. A fourth-order Bernstein polynomial function [105] is used for the unconverted rest (low pTt), converted rest (low pTt) and inclusive categories, an exponential function of a second-order polynomial for the unconverted central (low pTt), converted central (low pTt) and converted transition categories, and an exponential function for all others.

Studies to determine the potential bias have been performed using large samples of simulated background events complemented by data-driven estimates. The background shapes in the simulation have been crosschecked using data from control regions. The potential bias for a given model is estimated, separately for each category, by performing a maximum likelihood ﬁt to large samples of simulated background events in the mass range 100−160 GeV, of the sum of a signal plus the given background model. The signal shape is taken to follow the expectation for a SM Higgs boson; the signal yield is a free parameter of the ﬁt. The potential bias is deﬁned by the largest absolute signal yield obtained from the likelihood ﬁt to the simulated background samples for hypothesized Higgs boson masses in the range 110−150 GeV. A pre-selection of background parameterisations is made by requiring that the potential bias, as deﬁned above, is less than 20% of the statistical uncertainty on the ﬁtted signal yield. The pre-selected parameterisation in each category with the best expected sensitivity for mH = 125 GeV is selected as the background model.

The largest absolute signal yield as deﬁned above is taken as the systematic uncertainty on the background model. It amounts to ±(0.2−4.6) and ±(0.3−6.8) events, depending on the category for the 7 TeV and 8 TeV data samples, respectively. In the ﬁnal ﬁt to the data (see Section 5.7) a signal-like term is included in the likeli hood function for each category. This term incorporates the estimated potential bias, thus providing a conservative estimate of the uncertainty due to the background modeling.

5.6. Systematic uncertainties

Hereafter, in cases where two uncertainties are quoted, they refer to the 7 TeV and 8 TeV data, respectively. The dominant experimental uncertainty on the signal yield (±8%, ±11%) comes from the photon reconstruction and identiﬁcation eﬃciency, which is estimated with data using electrons from Z decays and

photons from Z → ee⁻γ events. Pile-up modelling also aﬀects the expected yields and contributes to the uncertainty (±4%). Further uncertainties on the signal yield are related to the trigger (±1%), photon isolation (±0.4%, ±0.5%) and luminosity (±1.8%, ±3.6%). Uncertainties due to the modelling of the underlying event are ±6% for VBF and ±30% for other production processes in the 2-jet category. Uncertainties on the predicted cross sections and branching ratio are sum marised in Section 8.

The uncertainty on the expected fractions of signal events in each category is described in the following. The uncertainty on the knowledge of the material in front of the calorimeter is used to derive the amount of possible event migration between the converted and unconverted categories (±4%). The uncertainty from pileup on the population of the converted and unconverted categories is ±2%. The uncertainty from the jet energy scale (JES) amounts to up to ±19% for the 2-jet category, and up to ±4% for the other categories. Uncertainties from the JVF modelling are ±12% (for the 8 TeV data) for the 2-jet category, estimated from Z+2-jets events by comparing data and MC. Diﬀerent PDFs and scale variations in the HqT calculations are used to derive possible event migration among categories (±9%) due to the modelling of the Higgs boson kinematics.

The total uncertainty on the mass resolution is ±14%. The dominant contribution (±12%) comes from the uncertainty on the energy resolution of the calorimeter, which is determined from Z→ e⁺e⁻events. Smaller contributions come from the imperfect knowledge of the material in front of the calorimeter, which aﬀects the extrapolation of the calibration from electrons to photons (±6%), and from pile-up (±4%).

Figure 4: The distributions of the invariant mass of diphoton candidates after all selections for the combined 7 TeV and 8 TeV data sample. The inclusive sample is shown in a) and a weighted version of the same sample in c); the weights are explained in the text. The result of a ﬁt to the data of the sum of a signal component ﬁxed to mH = 126.5 GeV and a background component described by a fourth-order Bernstein polynomial is superimposed. The residuals of the data and weighted data with respect to the respective ﬁtted background component are displayed in b) and d).

5.7. Results

The distributions of the invariant mass, mγγ, of the diphoton events, summed over all categories, are shown in Fig. 4(a) and (b). The result of a ﬁt including a signal component ﬁxed to mH = 126.5 GeV and a background component described by a fourth-order Bernstein polynomial is superimposed.

The statistical analysis of the data employs an unbinned likelihood function constructed from those of the ten categories of the 7 TeV and 8 TeV data samples. To demonstrate the sensitivity of this likelihood analy sis, Fig. 4(c) and (d) also show the mass spectrum ob tained after weighting events with category-dependent factors reﬂecting the signal-to-background ratios. The weight wi for events in category i ∈ [1, 10] for the 7 TeV and 8 TeV data samples is deﬁned to be ln (1 + Si/Bi), where Si is 90% of the expected signal for mH = 126.5 GeV, and Bi is the integral, in a window containing Si, of a background-only ﬁt to the data. The values Si/Bi have only a mild dependence on mH .

The statistical interpretation of the excess of events near mγγ = 126. 5 GeV in Fig. 4 is presented in Sec tion 9.

6. H→ WW^{⁽^∗⁾}→ eνµν channel

The signature for this channel is two opposite-charge leptons with large transverse momentum and a large momentum imbalance in the event due to the escaping neutrinos. The dominant backgrounds are non-resonant WW, tt¯, and Wt production, all of which have real W pairs in the ﬁnal state. Other important backgrounds include Drell-Yan events (pp→ Z/γ^{⁽^∗⁾}→ ee) with E^miss

that may arise from mismeasurement, W+jets events in which a jet produces an object reconstructed as the second electron or muon, and Wγ events in which the photon undergoes a conversion. Boson pair production (Wγ^∗/WZ^{⁽^∗⁾}and ZZ^{⁽^∗⁾}) can also produce opposite-charge lepton pairs with additional leptons that are not detected.

The analysis of the 8 TeV data presented here is focused on the mass range 110 < mH < 200 GeV. It follows the procedure used for the 7 TeV data, described in Ref. [106], except that more stringent criteria are ap plied to reduce the W+jets background and some selections have been modiﬁed to mitigate the impact of the higher instantaneous luminosity at the LHC in 2012. In particular, the higher luminosity results in a larger Drell-Yan background to the same-ﬂavour ﬁnal states, due to the deterioration of the missing transverse momentum resolution. For this reason, and the fact that the eµ ﬁnal state provides more than 85% of the sensitivity of the search, the same-ﬂavour ﬁnal states have not been used in the analysis described here.

6.1. Event selection

For the 8 TeV H→ WW^{⁽^∗⁾}→ eνµν search, the data are selected using inclusive single-muon and single-electron triggers. Both triggers require an isolated lepton with pT > 24 GeV. Quality criteria are applied to suppress non-collision backgrounds such as cosmic-ray muons, beam-related backgrounds, and noise in the calorimeters. The primary vertex selection fol lows that described in Section 4. Candidates for the H→ WW^{⁽^∗⁾}→ eνµν search are pre-selected by requiring exactly two opposite-charge leptons of diﬀerent ﬂavours, with pT thresholds of 25 GeV for the leading lepton and 15 GeV for the sub-leading lepton. Events are classiﬁed into two exclusive lepton channels depending on the ﬂavour of the leading lepton, where eµ (µe) refers to events with a leading electron (muon). The dilepton invariant mass is required to be greater than 10 GeV.

The lepton selection and isolation have more stringent requirements than those used for the H → ZZ^{⁽^∗⁾}→ 4e analysis (see Section 4), to reduce the larger back ground from non-prompt leptons in the eνeν ﬁnal state. Electron candidates are selected using a combination of tracking and calorimetric information [85]; the criteria are optimised for background rejection, at the expense of some reduced eﬃciency. Muon candidates are re stricted to those with matching MS and ID tracks [84], and therefore are reconstructed over |η| < 2.5. The isolation criteria require the scalar sums of the pT of charged particles and of calorimeter topological clusters within ΔR = 0.3 of the lepton direction (excluding the lepton itself) each to be less than 0.12-0.20 times the lepton pT. The exact value diﬀers between the criteria for tracks and calorimeter clusters, for both electrons and muons, and depends on the lepton pT. Jet selec tions follow those described in Section 5.3, except that the JVF is required to be greater than 0.5.

Since two neutrinos are present in the signal ﬁnal

_Emiss

state, events are required to have large E^miss. is

the negative vector sum of the transverse momenta of the reconstructed objects, including muons, electrons, photons, jets, and clusters of calorimeter cells not associated with these objects. The quantity E^missused

T,rel

in this analysis is required to be greater than 25 GeV

_Emiss

and is deﬁned as: E^miss= sin Δφmin, where Δφmin

T,rel T is min(Δφ, ^π), and E^missis the magnitude of the vec

2T _{_tor_E}miss

. Here, Δφ is the angle between E^missand the

TT transverse momentum of the nearest lepton or jet with

_{_,_E}miss

pT > 25 GeV. Compared to E^misshas increased

TT,rel

rejection power for events in which the E^missis gener-

ated by a neutrino in a jet or the mismeasurement of an object, since in those events the E^misstends to point in

the direction of the object. After the lepton isolation and

_Emiss

requirements that deﬁne the pre-selected sample,

T,rel

the multijet background is negligible and the Drell-Yan background is much reduced. The Drell-Yan contribution becomes very small after the topological selections, described below, are applied.

The background rate and composition depend significantly on the jet multiplicity, as does the signal topology. Without accompanying jets, the signal originates almost entirely from the ggF process and the background is dominated by WW events. In contrast, when produced in association with two or more jets, the signal contains a much larger contribution from the VBF process compared to the ggF process, and the background is dominated by tt production. Therefore, to maximise the sensitivity to SM Higgs events, further selection criteria depending on the jet multiplicity are applied to the pre-selected sample. The data are subdivided into 0-jet, 1-jet and 2-jet search channels according to the number of jets in the ﬁnal state, with the 2-jet channel also including higher jet multiplicities.

Owing to spin correlations in the WW^{⁽^∗⁾}system arising from the spin-0 nature of the SM Higgs boson and the V-A structure of the W boson decay vertex, the charged leptons tend to emerge from the primary ver tex pointing in the same direction [107]. This kinematic feature is exploited for all jet multiplicities by requiring that |Δφee| < 1.8, and the dilepton invariant mass, mee, be less than 50 GeV for the 0-jet and 1-jet channels. For the 2-jet channel, the mee upper bound is increased to 80 GeV.

In the 0-jet channel, the magnitude p^ee_Tof the transverse momentum of the dilepton system, p^ee= p_T^{^e¹}+p^e_T²,

is required to be greater than 30 GeV. This improves the rejection of the Drell-Yan background.

In the 1-jet channel, backgrounds from top quark production are suppressed by rejecting events containing a b-tagged jet, as determined using a b-tagging algorithm that uses a neural network and exploits the topology of weak decays of b-and c -hadrons [108]. The total trans verse momentum, p^tot, deﬁned as the magnitude of the

T _Tj _{+ E}miss

vector sum p^tot= p^{^e¹}+ p^{^e²}+ p, is required

TTT T

to be smaller than 30 GeV to suppress top background events that have jets with pT below the threshold deﬁned for jet counting. In order to reject the background from Z→ ττ, the ττ invariant mass, mττ, is computed under the assumptions that the reconstructed leptons are τ lepton decay products. In addition the neutrinos produced in these decays are assumed to be the only source of

_Emiss

_T and to be collinear with the leptons [109]. Events with |mττ − mZ | < 25 GeV are rejected if the collinear approximation yields a physical solution.

The 2-jet selection follows the 1-jet selection described above, with the p^totdeﬁnition modiﬁed to in-

clude all selected jets. Motivated by the VBF topology, several additional criteria are applied to the tag jets, deﬁned as the two highest-pT jets in the event. These are required to be separated in rapidity by a distance |Δyjj| > 3.8 and to have an invariant mass, mjj, larger than 500 GeV. Events with an additional jet with pT > 20 GeV between the tag jets (yj1 < y < yj2) are rejected.

A transverse mass variable, mT [110], is used to test for the presence of a signal for all jet multiplicities. This variable is deﬁned as:

mT =(E^ee+ E^miss)²−|p^ee+ E^miss|²,

TT TT

where E^ee=|p^ee|²+ m². The statistical analysis of

TT ee

the data uses a ﬁt to the mT distribution in the signal region after the Δφee requirement (see Section 6.4), which results in increased sensitivity compared to the analysis described in Ref. [111].

For a SM Higgs boson with mH = 125 GeV, the cross section times branching ratio to the eνµν ﬁnal

√

state is 88 fb for s = 7 TeV, increasing to 112 fb at

√

s = 8 TeV. The combined acceptance times eﬃciency of the 8 TeV 0-jet and 1-jet selection relative to the ggF production cross section times branching ratio is about 7.4%. The acceptance times eﬃciency of the 8 TeV 2-jet selection relative to the VBF production cross section times branching ratio is about 14%. Both of these ﬁgures are based on the number of events selected before the ﬁnal mT criterion is applied (as described in Sec tion 6.4).

6.2. Background normalisation and control samples

The leading backgrounds from SM processes producing two isolated high-pT leptons are WW and top (in this section, “top” background always includes both tt¯and single top, unless otherwise noted). These are estimated using partially data-driven techniques based on normalising the MC predictions to the data in control regions dominated by the relevant background source. The W+jets background is estimated from data for all jet multiplicities. Only the small backgrounds from Drell-Yan and diboson processes other than WW, as well as the WW background for the 2-jet analysis, are estimated using MC simulation.

The control and validation regions are deﬁned by selections similar to those used for the signal region but with some criteria reversed or modiﬁed to obtain signal-depleted samples enriched in a particular background. The term “validation region” distinguishes these regions from the control regions that are used to directly normalise the backgrounds. Some control regions have signiﬁcant contributions from backgrounds other than the targeted one, which introduces dependencies among the background estimates. These correlations are fully incorporated in the ﬁt to the mT distribution. In the following sections, each background estimate is described after any others on which it depends. Hence, the largest background (WW) is described last.

6.2.1. W+jets background estimation

The W+jets background contribution is estimated using a control sample of events where one of the two leptons satisﬁes the identiﬁcation and isolation criteria de scribed in Section 6.1, and the other lepton fails these criteria but satisﬁes a loosened selection (denoted “antiidentiﬁed”). Otherwise, events in this sample are required to pass all the signal selections. The dominant contribution to this sample comes from W+jets events in which a jet produces an object that is reconstructed as a lepton. This object may be either a true electron or muon from the decay of a heavy quark, or else a product of the fragmentation identiﬁed as a lepton candidate.

The contamination in the signal region is obtained by scaling the number of events in the data control sample by a transfer factor. The transfer factor is deﬁned here as the ratio of the number of identiﬁed lepton candidates passing all selections to the number of anti-identiﬁed leptons. It is calculated as a function of the anti-identiﬁed lepton pT using a data sample dominated by QCD jet production (dijet sample) after subtracting the residual contributions from leptons produced by leptonic W and Z decays, as estimated from data. The small remaining lepton contamination, which includes Wγ^{⁽^∗⁾}/WZ^{⁽^∗⁾}events, is subtracted using MC simulation.

The processes producing the majority of same-charge dilepton events, W+jets, Wγ^{⁽^∗⁾}/WZ^{⁽^∗⁾}and Z^{⁽^∗⁾}Z^{⁽^∗⁾}, are all backgrounds in the opposite-charge signal region. W+jets and Wγ^{⁽^∗⁾}backgrounds are particularly important in a search optimised for a low Higgs boson mass hypothesis. Therefore, the normalisation and kinematic features of same-charge dilepton events are used to validate the predictions of these backgrounds. The predicted number of same-charge events after the E^missand

T,rel

zero-jet requirements is 216 ± 7 (stat) ± 42 (syst), while 182 events are observed in the data. Satisfactory agreement between data and simulation is observed in various kinematic distributions, including those of Δφee (see Fig. 5(a)) and the transverse mass.

6.2.2. Top control sample

In the 0-jet channel, the top quark background prediction is ﬁrst normalised using events satisfying the pre selection criteria described in Section 6.1. This sample is selected without jet multiplicity or b-tagging requirements, and the majority of events contain top quarks. Non-top contributions are subtracted using predictions from simulation, except for W+jets, which is estimated using data. After this normalisation is performed, the fraction of events with zero jets that pass all selections is evaluated. This fraction is small (about 3%), since the top quark decay t→ Wb has a branching ratio of nearly

Figure 5: Validation and control distributions for the H→ WW^{⁽^∗⁾}→ eνµν analysis. a) Δφee distribution in the same-charge validation region after the E^missand zero-jet requirements. b)

T,rel

mT distribution in the WW control region for the 0-jet channel. The eµ and µe ﬁnal states are combined. The hashed area indicates the total uncertainty on the background prediction. The expected signal for mH = 125 GeV is negligible and therefore not visible.

1. Predictions of this fraction from MC simulation are sensitive to theoretical uncertainties such as the modelling of initial-and ﬁnal-state radiation, as well as experimental uncertainties, especially that on the jet energy scale. To reduce the impact of these uncertainties, the top quark background determination uses data from a b-tagged control region in which the one-to-two jet ra tio is compared to the MC simulation [112]. The result ing correction factor to a purely MC-based background estimate after all selections amounts to 1.11±0.06 (stat).

In the 1-jet and 2-jet analyses, the top quark background predictions are normalised to the data using control samples deﬁned by reversing the b-jet veto and removing the requirements on Δφee and mee. The |Δyjj| and mjj requirements are included in the deﬁnition of the 2-jet control region. The resulting samples are dominated by top quark events. The small contributions from other sources are taken into account using MC simulation and the data-driven W+jets estimate. Good agreement between data and MC simulation is observed for the total numbers of events and the shapes of the mT distributions. The resulting normalisation factors are

1.11 ± 0.05 for the 1-jet control region and 1.01 ± 0.26 for the 2-jet control region. Only the statistical uncertainties are quoted.

6.2.3. WW control sample The MC predictions of the WW background in the 0-jet and 1-jet analyses, summed over lepton ﬂavours, are normalised using control regions deﬁned with the same selections as for the signal region except that the Δφee requirement is removed and the upper bound on mee is replaced with a lower bound: mee > 80 GeV. The numbers of events and the shape of the mT distribution in the control regions are in good agreement between data and MC, as shown in Fig. 5(b). WW production contributes about 70% of the events in the 0-jet control region and about 45% in the 1-jet region. Contaminations from sources other than WW are derived as for the signal region, including the data-driven W+jets and top estimates. The resulting normalisation factors with their associated statistical uncertainties are 1.06±0.06 for the

0-jet control region and 0.99 ± 0.15 for the 1-jet control region.

6.3. Systematic uncertainties

The systematic uncertainties that have the largest impact on the sensitivity of the search are the theoretical uncertainties associated with the signal. These are de scribed in Section 9. The main experimental uncertain ties are associated with the JES, the jet energy resolution (JER), pile-up, E^miss, the b-tagging eﬃciency, the

W+jets transfer factor, and the integrated luminosity. The largest uncertainties on the backgrounds include WW normalisation and modelling, top normalisation, and Wγ^{⁽^∗⁾}normalisation. The 2-jet systematic uncertainties are dominated by the statistical uncertainties in the data and the MC simulation, and are therefore not discussed further.

Variations of the jet energy scale within the systematic uncertainties can cause events to migrate between the jet bins. The uncertainty on the JES varies from ±2% to ±9% as a function of jet pT and η for jets with pT > 25 GeV and |η| < 4. 5 [101]. The largest impact of this uncertainty on the total signal (background) yield amounts to 7% (4%) in the 0-jet (1-jet) bin. The uncertainty on the JER is estimated from in situ measurements and it impacts mostly the 1-jet channel, where its eﬀect on the total signal and background yields is 4% and 2%, respectively. An additional contribution to the JES uncertainty arises from pile-up, and is estimated to vary between ±1% and ±5% for multiple pp collisions in the same bunch crossing and up to ±10% for neighbouring bunch crossings. This uncertainty aﬀects mainly the 1-jet channel, where its impact on the signal and background yields is 4% and 2%, respectively. JES and lepton momentum scale uncertainties are propagated to the E^missmeasurement. Additional contri-

butions to the E^missuncertainties arise from jets with

pT < 20 GeV and from low-energy calorimeter deposits not associated with reconstructed physics objects [113]. The impact of the E^missuncertainty on the total signal

and background yields is ∼3%. The eﬃciency of the b-tagging algorithm is calibrated using samples contain ing muons reconstructed in the vicinity of jets [114]. The uncertainty on the b-jet tagging eﬃciency varies between ±5% and ±18% as a function of the jet pT, and its impact on the total background yield is 10% for the 1-jet channel. The uncertainty in the W+jets transfer factor is dominated by diﬀerences in jet properties between dijet and W+jets events as observed in MC simulations. The total uncertainty on this background is approximately ±40%, resulting in an uncertainty on the total background yield of 5%. The uncertainty on the integrated luminosity is ±3.6%.

A ﬁt to the distribution of mT is performed in order to obtain the signal yield for each mass hypoth esis (see Section 6.4). Most theoretical and experimental uncertainties do not produce statistically significant changes to the mT distribution. The uncertainties that do produce signiﬁcant changes of the distribution of mT have no appreciable eﬀect on the ﬁnal results, with the exception of those associated with the WW background. In this case, an uncertainty is included to take into account diﬀerences in the distribution of mT and normalisation observed between the MCFM [115], MC@NLO+HERWIG and POWHEG+PYTHIA generators. The potential impact of interference between resonant (Higgs-mediated) and non-resonant gg→ WW diagrams [116] for mT > mH was investigated and found to be negligible. The eﬀect of the WW normalisation, modelling, and shape systematics on the total background yield is 9% for the 0-jet channel and 19% for the 1-jet channel. The uncertainty on the shape of the total background is dominated by the uncertainties on the normalisations of the individual backgrounds. The main uncertainties on the top background in the 0-jet analysis include those associated with interference effects between tt¯and single top, initial state an ﬁnal state radiation, b-tagging, and JER. The impact on the total background yield in the 0-jet bin is 3%. For the 1-jet analysis, the impact of the top background on the total yield is 14%. Theoretical uncertainties on the Wγ background normalisation are evaluated for each jet bin using the procedure described in Ref. [117]. They are ±11% for the 0-jet bin and ±50% for the 1-jet bin. For Wγ^∗with mee < 7 GeV, a k-factor of 1.3 ±0.3 is applied to the MadGraph LO prediction based on the comparison with the MCFM NLO calculation. The k-factor for Wγ^∗/WZ^{⁽^∗⁾}with mee > 7 GeV is 1.5 ± 0.5. These uncertainties aﬀect mostly the 1-jet channel, where their impact on the total background yield is approximately 4%.

Table 5: The expected numbers of signal (mH = 125 GeV) and background events after all selections, including a cut on the transverse mass of 0.75 mH < mT < mH for mH = 125 GeV. The observed numbers of events in data are also displayed. The eµ and µe channels are combined. The uncertainties shown are the combination of the statistical and all systematic uncertainties, taking into account the constraints from control samples. For the 2-jet analysis, backgrounds with fewer than 0.01 expected events are marked with ‘-’.

	0-jet	1-jet	2-jet
Signal	20 ± 4	5 ± 2	0.34 ± 0.07
WW	101 ± 13	12 ± 5	0.10 ± 0.14
WZ(∗)/ZZ/Wγ(∗)	12 ± 3	1.9 ± 1.1	0.10 ± 0.10
t¯t	8 ± 2	6 ± 2	0.15 ± 0.10
tW/tb/tqb	3.4 ± 1.5	3.7 ± 1.6	-
Z/γ∗ + jets	1.9 ± 1.3	0.10 ± 0.10	-
W + jets	15 ± 7	2 ± 1	-
Total Background	142 ± 16	26 ± 6	0.35 ± 0.18
Observed	185	38	0

6.4. Results

Table 5 shows the numbers of events expected from a SM Higgs boson with mH = 125 GeV and from the backgrounds, as well as the numbers of candidates observed in data, after application of all selection criteria plus an additional cut on mT of0.75 mH < mT < mH . The uncertainties shown in Table 5 include the system atic uncertainties discussed in Section 6.3, constrained by the use of the control regions discussed in Sec tion 6.2. An excess of events relative to the background expectation is observed in the data.

Figure 6 shows the distribution of the transverse mass after all selection criteria in the 0-jet and 1-jet channels combined, and for both lepton channels together.

The statistical analysis of the data employs a binned likelihood function constructed as the product of Poisson probability terms for the eµ channel and the µe

Figure 6: Distribution of the transverse mass, mT, in the 0-jet and 1-jet analyses with both eµ and µe channels combined, for events satisfying all selection criteria. The expected signal for mH = 125 GeV is shown stacked on top of the background prediction. The W+jets background is estimated from data, and WW and top background MC predictions are normalised to the data using control regions. The hashed area indicates the total uncertainty on the background prediction.

channel. The mass-dependent cuts on mT described above are not used. Instead, the 0-jet (1-jet) signal regions are subdivided into ﬁve (three) mT bins. For the 2-jet signal region, only the results integrated over mT are used, due to the small number of events in the ﬁnal sample. The statistical interpretation of the observed excess of events is presented in Section 9.

7. Statistical procedure

The statistical procedure used to interpret the data is described in Refs. [17, 118–121]. The parameter of in terest is the global signal strength factor µ, which acts as a scale factor on the total number of events predicted by the Standard Model for the Higgs boson signal. This factor is deﬁned such that µ = 0 corresponds to the background-only hypothesis and µ = 1 corresponds to the SM Higgs boson signal in addition to the background. Hypothesized values of µ are tested with a statistic λ(µ ) based on the proﬁle likelihood ratio [122]. This test statistic extracts the information on the signal strength from a full likelihood ﬁt to the data. The likelihood function includes all the parameters that describe the systematic uncertainties and their correlations.

Exclusion limits are based on the CLs prescrip tion [123]; a value of µ is regarded as excluded at 95% CL when CLs is less than 5%. A SM Higgs boson with mass mH is considered excluded at 95% conﬁdence level (CL) when µ = 1 is excluded at that mass. The signiﬁcance of an excess in the data is ﬁrst quantiﬁed with the local p0, the probability that the background can produce a ﬂuctuation greater than or equal to the excess observed in data. The equivalent formulation in terms of number of standard deviations, Zl, is referred to as the local signiﬁcance. The global significance of a local excess anywhere in the search region, correcting for the “look-elsewhere” eﬀect, is estimated with the method described in Ref. [124].

The statistical tests are performed in steps of values of the hypothesized Higgs boson mass mH . The asymp totic approximation [122] upon which the results are based has been validated previously [17].

The combination of individual search sub-channels for a speciﬁc Higgs boson decay, and the full combination of all search channels, are based on the global signal strength factor µ and on the identiﬁcation of the nuisance parameters that correspond to correlated sources of systematic uncertainty.

8. Correlated systematic uncertainties

The individual search channels that enter the combi nation are summarised in Table 6.

The main uncorrelated systematic uncertainties are described in Sections 4–6 for the H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνeν channels and in Ref. [17] for the other channels. They include the background normalisations or background model parameters from control regions or sidebands, the Monte Carlo simulation statistical uncertainties and the theoretical uncertainties aﬀecting the background processes.

The main sources of correlated systematic uncertainties are the following.

Integrated luminosity: The uncertainty on the integrated luminosity is considered as fully correlated among channels and amounts to ±3.9% for the 7 TeV data [132, 133], except for the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels which were re-analysed; the uncertainty is ± 1.8% [92] for these channels. The uncertainty is ±3.6% for the 8 TeV data.
Electron and photon trigger identiﬁcation: The uncertainties in the trigger and identiﬁcation eﬃciencies are treated as fully correlated for electrons and photons.
Electron and photon energy scales: The electron and photon energy scales in the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels are described by ﬁve parameters, which provide a detailed account of the sources of systematic uncertainty. They are related to the calibration method, the presampler energy scale in the barrel and end-cap calorimeters, and the material description upstream of the calorimeters.

Muon reconstruction: The uncertainties aﬀecting muons are separated into those related to the ID and MS, in order to obtain a better description of the correlated eﬀects among channels using diﬀerent muon identiﬁcation criteria and diﬀerent ranges of muon pT.
Jet energy scale and missing transverse energy: The jet energy scale and jet energy resolution are affected by uncertainties which depend on the pT, η, and ﬂavour of the jet. A simpliﬁed scheme is used in which independent JES and JER nuisance parameters are associated with ﬁnal states with signiﬁcantly diﬀerent kinematic selections and sensitivity to scattering processes with diﬀerent kinematic distributions or ﬂavour composition. This scheme includes a speciﬁc treatment for b-jets. The sensitivity of the results to various assumptions about the correlation between these sources of uncertainty has been found to be negligible. An uncorrelated component of the uncertainty on E^missis in-

cluded, in addition to the JES uncertainty, which is due to low energy jet activity not associated with reconstructed physics objects.

6. Theory uncertainties: Correlated theoretical uncertainties aﬀect mostly the signal predictions. The QCD scale uncertainties for mH=125 GeV amount to

+7%

_{₋_8%}for the ggF process, ±1% for the VBF and WH/ZH processes, and for the t¯

^{⁺^4%}tH process [52, 53]; the

−9%

small dependence of these uncertainties on mH is taken into account. The uncertainties on the predicted branching ratios amount to ±5%. The uncertainties related to the parton distribution functions amount to ±8% for the predominantly gluon-initiated ggF and t¯

tH processes, and ±4% for the predominantly quark-initiated VBF and WH/ZH processes [78, 134–136]. The theoretical uncertainty associated with the exclusive Higgs boson production process with additional jets in the H→ γγ, H→ WW^{⁽^∗⁾}→ eνeν and H → τ⁺τ⁻channels is estimated using the prescription of Refs. [53, 117, 118], with the noticeable diﬀerence that an explicit calculation of the gluon-fusion process at NLO using MCFM [137] in the 2-jet category reduces the uncertainty on this non-negligible contribution to 25 %. An additional theoretical uncertainty on the signal normalisation of ±150%×(mH /TeV)³(e.g. ±4% for mH = 300 GeV) accounts for eﬀects related to oﬀ-shell Higgs boson pro duction and interference with other SM processes [53].

Sources of systematic uncertainty that aﬀect both the 7 TeV and the 8 TeV data are taken as fully correlated. The uncertainties on background estimates based on control samples in the data are considered uncorrelated between the 7 TeV and 8 TeV data.

Table 6: Summary of the individual channels entering the combination. The transition points between separately optimised mH regions are indicated where applicable. In channels sensitive to associated production of the Higgs boson, V indicates a W or Z boson. The symbols ⊗ and ⊕ represent direct products and sums over sets of selection requirements, respectively.


Higgs Boson Decay	Subsequent Decay	Sub-Channels	mH Range[GeV]	L dt [fb−1]	Ref.
		2011 √ s =7 TeV

H → ZZ(∗)	4e eeν¯ν eeq ¯q	{4e, 2e2µ, 2µ2e, 4µ}{ee, µµ} ⊗ {low, high pile-up}{b-tagged, untagged}	110–600 200–280–600 200–300–600	4.8 4.7 4.7	[87] [125] [126]
H → γγ	–	10 categories {pTt ⊗ ηγ ⊗ conversion} ⊕ {2-jet}	110–150	4.8	[127]
H → WW(∗)	eνeν eνqq '	{ee, eµ/µe, µµ} ⊗ {0-jet, 1-jet, 2-jet} ⊗ {low, high pile-up}{e, µ} ⊗ {0-jet, 1-jet, 2-jet}	110–200–300–600 300–600	4.7 4.7	[106] [128]
H → ττ	τlepτlep τlepτhad τhadτhad	{eµ} ⊗ {0-jet} ⊕ {ee} ⊗ {1-jet, 2-jet, VH}{e, µ} ⊗ {0-jet} ⊗ {Emiss T < 20 GeV, Emiss T ≥ 20 GeV}⊕ {e, µ} ⊗ {1-jet} ⊕ {e} ⊗ {2-jet}{1-jet}	110–150 110–150 110–150	4.7 4.7 4.7	[129]
VH → Vbb	Z → νν W → eν Z → ee	Emiss T ∈ {120 − 160, 160 − 200, ≥ 200 GeV}pW T ∈ {< 50, 50 − 100, 100 − 200, ≥ 200 GeV}pZ T ∈ {< 50, 50 − 100, 100 − 200, ≥ 200 GeV}√	110–130 110–130 110–130	4.6 4.7 4.7	[130]

2012 s =8 TeV

H → ZZ(∗)	4e	{4e, 2e2µ, 2µ2e, 4µ}	110–600	5.8	[87]
H → γγ	–	10 categories {pTt ⊗ ηγ ⊗ conversion} ⊕ {2-jet}	110–150	5.9	[127]
H → WW(∗)	eνµν	{eµ, µe} ⊗ {0-jet, 1-jet, 2-jet}	110–200	5.8	[131]

Table 7: Characterisation of the excess in the H → ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνeν channels and the combination of all channels listed in Table 6. The mass value mmax for which the local signiﬁcance is maximum, the maximum observed local signiﬁcance Zl and the expected local signiﬁcance E(Zl) in the presence of a SM Higgs boson signal at mmax are given. The best ﬁt value of the signal strength parameter ˆµ at mH = 126 GeV is shown with the total uncertainty. The expected and observed mass ranges excluded at 95% CL (99% CL, indicated by a *) are

√√

also given, for the combined s = 7 TeV and s = 8 TeV data.

Search channel	Dataset	mmax [GeV]	Zl [σ]	E(Zl) [σ]	ˆµ(mH = 126 GeV)	Expected exclusion [GeV]	Observed exclusion [GeV]
	7 TeV	125.0	2.5	1.6	1.7 ± 1.1
H → ZZ(∗) → 4e	8 TeV	125.5	2.6	2.1	1.3 ± 0.8
	7 & 8 TeV	125.0	3.6	2.7	1.4 ± 0.6	124–164, 176–500	131–162, 170–460
	7 TeV	126.0	3.4	1.6	2.2 ± 0.7
H→ γγ	8 TeV	127.0	3.2	1.9	1.5 ± 0.6
	7 & 8 TeV	126.5	4.5	2.5	1.8 ± 0.5	110–140	112–123, 132–143
	7 TeV	135.0	1.1	3.4	0.5 ± 0.6
H→ WW(∗)→ eνeν	8 TeV	120.0	3.3	1.0	1.9 ± 0.7
	7 & 8 TeV	125.0	2.8	2.3	1.3 ± 0.5	124–233	137–261
	7 TeV	126.5	3.6	3.2	1.2 ± 0.4
Combined	8 TeV 7 & 8 TeV	126.5 126.5	4.9 6.0	3.8 4.9	1.5 ± 0.4 1.4 ± 0.3	110–582 113–532 (*)	111–122, 131–559 113–114, 117–121, 132–527 (*)

9. Results

The addition of the 8 TeV data for the H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνµν channels, as well as the improvements to the analyses of the 7 TeV data in the ﬁrst two of these channels, bring a signiﬁcant gain in sensitivity in the low-mass region with respect to the previous combined search [17].

9.1. Excluded mass regions

The combined 95% CL exclusion limits on the production of the SM Higgs boson, expressed in terms of the signal strength parameter µ , are shown in Fig. 7(a) as a function of mH . The expected 95% CL exclusion region covers the mH range from 110 GeV to 582 GeV. The observed 95% CL exclusion regions are 111–122 GeV and 131–559 GeV. Three mass regions are excluded at 99% CL, 113–114, 117–121 and 132– 527 GeV, while the expected exclusion range at 99% CL is 113–532 GeV.

9.2. Observation of an excess of events

An excess of events is observed near mH=126 GeV in the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels, both of which

Figure 7: Combined search results: (a) The observed (solid) 95% CL limits on the signal strength as a function of mH and the expectation (dashed) under the background-only hypothesis. The dark and light shaded bands show the ±1σ and ±2σ uncertainties on the background-only expectation. (b) The observed (solid) local p0 asa function of mH and the expectation (dashed) for a SM Higgs boson signal hypothesis (µ = 1) at the given mass. (c) The best-ﬁt signal strength ˆµ as a function of mH . The band indicates the approximate 68% CL interval around the ﬁtted value.

provide fully reconstructed candidates with high reso lution in invariant mass, as shown in Figures 8(a) and 8(b). These excesses are conﬁrmed by the highly sen sitive but low-resolution H→ WW^{⁽^∗⁾}→ eνeν channel, as shown in Fig. 8(c).

The observed local p0 values from the combination of channels, using the asymptotic approximation, are shown as a function of mH in Fig. 7(b) for the full mass range and in Fig. 9 for the low mass range.

The largest local signiﬁcance for the combination of the 7 and 8 TeV data is found for a SM Higgs boson mass hypothesis of mH =126.5 GeV, where it reaches

6.0 σ, with an expected value in the presence of a SM Higgs boson signal at that mass of 4.9 σ (see also Ta ble 7). For the 2012 data alone, the maximum local signiﬁcance for the H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and

Figure 8: The observed local p0 as a function of the hypothesized Higgs boson mass for the (a) H→ ZZ^{⁽^∗⁾}→ 4e, (b) H→ γγ and (c) H→ WW^{⁽^∗⁾}→ eνeν channels. The dashed curves show the expected local p0 under the hypothesis of a SM Higgs boson signal at that mass.

√

Results are shown separately for the s = 7 TeV data (dark, blue), the

√

s = 8 TeV data (light, red), and their combination (black).

H→ WW^{⁽^∗⁾}→ eνµν channels combined is 4.9 σ, and occurs at mH = 126.5 GeV (3.8 σ expected).

The signiﬁcance of the excess is mildly sensitive to uncertainties in the energy resolutions and energy scale systematic uncertainties for photons and electrons; the eﬀect of the muon energy scale systematic uncertainties is negligible. The presence of these uncertainties, evaluated as described in Ref. [138], reduces the local signiﬁcance to 5.9 σ.

The global signiﬁcance of a local 5.9 σ excess anywhere in the mass range 110–600 GeV is estimated to be approximately 5.1 σ, increasing to 5.3 σ in the range 110–150 GeV, which is approximately the mass range not excluded at the 99% CL by the LHC combined SM Higgs boson search [139] and the indirect constraints from the global ﬁt to precision electroweak measure ments [12].

Figure 9: The observed (solid) local p0 as a function of mH in the low mass range. The dashed curve shows the expected local p0 under the hypothesis of a SM Higgs boson signal at that mass with its ±1σ band. The horizontal dashed lines indicate the p-values corresponding to signiﬁcances of 1 to 6 σ.

9.3. Characterising the excess

The mass of the observed new particle is estimated using the proﬁle likelihood ratio λ(mH ) for H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ, the two channels with the highest mass resolution. The signal strength is allowed to vary independently in the two channels, although the result is essentially unchanged when restricted to the SM hypothesis µ = 1. The leading sources of systematic uncertainty come from the electron and photon energy scales and resolutions. The resulting estimate for the mass of the observed particle is

126.0 ± 0.4 (stat) ± 0.4 (sys) GeV.

The best-ﬁt signal strength ˆµ is shown in Fig. 7(c) as a function of mH . The observed excess corresponds to µˆ= 1.4 ± 0.3 for mH = 126 GeV, which is consistent with the SM Higgs boson hypothesis µ = 1. A summary of the individual and combined best-ﬁt values of the strength parameter for a SM Higgs boson mass hy pothesis of 126 GeV is shown in Fig. 10, while more information about the three main channels is provided in Table 7.

In order to test which values of the strength and mass of a signal hypothesis are simultaneously consistent with the data, the proﬁle likelihood ratio λ(µ, mH ) is used. In the presence of a strong signal, it will produce closed contours around the best-ﬁt point (ˆµ, mˆH ), while in the absence of a signal the contours will be upper limits on µ for all values of mH .

Asymptotically, the test statistic −2 ln λ(µ, mH ) is distributed as a χ²distribution with two degrees of freedom. The resulting 68% and 95% CL contours for the H→ γγ and H→ WW^{⁽^∗⁾}→ eνeν channels are shown in

Figure 10: Measurements of the signal strength parameter µ for mH =126 GeV for the individual channels and their combination.

Fig. 11, where the asymptotic approximations have been validated with ensembles of pseudo-experiments. Similar contours for the H→ ZZ^{⁽^∗⁾}→ 4e channel are also shown in Fig. 11, although they are only approximate conﬁdence intervals due to the smaller number of candidates in this channel. These contours in the (µ, mH) plane take into account uncertainties in the energy scale and resolution.

The probability for a single Higgs boson-like particle to produce resonant mass peaks in the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels separated by more than the observed mass diﬀerence, allowing the signal strengths to vary independently, is about 20%.

The contributions from the diﬀerent production modes in the H→ γγ channel have been studied in order to assess any tension between the data and the ratios of the production cross sections predicted in the Standard Model. A new signal strength parameter µi is introduced for each production mode, deﬁned by µi = σi/σi,SM. In order to determine the values of (µi,µ j) that are simultaneously consistent with the data, the proﬁle likelihood ratio λ(µi,µ j) is used with the measured mass treated as a nuisance parameter.

Since there are four Higgs boson production modes at the LHC, two-dimensional contours require either some µi to be ﬁxed, or multiple µi to be related in some way. Here, µggF and µt¯

tH have been grouped together as they scale with the t¯

tH coupling in the SM, and are denoted by the common parameter µggF+t¯

tH . Similarly, µVBF and µVH have been grouped together as they scale with the WWH/ZZH coupling in the SM, and are denoted by the common parameter µVBF+VH . Since the distribution of signal events among the 10 categories of the H→ γγ search is sensitive to these factors, constraints in the

Figure 11: Conﬁdence intervals in the (µ, mH ) plane for the H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ, and H→ WW^{⁽^∗⁾}→ eνeν channels, including all systematic uncertainties. The markers indicate the maximum likelihood estimates (ˆµ, mˆH ) in the corresponding channels (the maximum likelihood estimates for H→ ZZ^{⁽^∗⁾}→ 4e and H→ WW^{⁽^∗⁾}→ eνeν coincide).

plane of µggF+t¯

tH × B/BSM and µVBF+VH × B/BSM, where B is the branching ratio for H→ γγ, can be obtained (Fig. 12). Theoretical uncertainties are included so that the consistency with the SM expectation can be quantiﬁed. The data are compatible with the SM expectation at the 1.5 σ level.

10. Conclusion

Searches for the Standard Model Higgs boson have been performed in the H→ ZZ^{⁽^∗⁾}→ 4e, H→ γγ and H→ WW^{⁽^∗⁾}→ eνµν channels with the ATLAS experiment at the LHC using 5.8–5.9 fb^⁻¹of pp collision data recorded during April to June 2012 at a centre-of-mass energy of 8 TeV. These results are combined with ear lier results [17], which are based on an integrated lu minosity of 4.6–4.8 fb^⁻¹recorded in 2011 at a centreof-mass energy of 7 TeV, except for the H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ channels, which have been updated with the improved analyses presented here.

The Standard Model Higgs boson is excluded at 95% CL in the mass range 111–559 GeV, except for the narrow region 122–131 GeV. In this region, an excess of events with signiﬁcance 5.9 σ, corresponding to p0 = 1.7 × 10^⁻⁹, is observed. The excess is driven by the two channels with the highest mass resolution, H→ ZZ^{⁽^∗⁾}→ 4e and H→ γγ, and the equally sensitive but low-resolution H→ WW^{⁽^∗⁾}→ eνeν channel. Taking into account the entire mass range of the search, 110– 600 GeV, the global signiﬁcance of the excess is 5.1 σ, which corresponds to p0 = 1.7 × 10^⁻⁷.

tH (µVBF+VH ) is a common scale factor for the ggF and t¯

tH (VBF and VH) production cross sections. The best ﬁt to the data (+) and 68% (full) and 95% (dashed) CL contours are also indicated, as well as the SM expectation (×).

These results provide conclusive evidence for the discovery of a new particle with mass

126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The signal strength parameter µ has the value 1.4 ± 0.3 at the ﬁtted mass, which is consistent with the SM Higgs boson hypothesis µ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observation in the diphoton channel disfavours the spin-1 hypothe sis [140, 141]. Although these results are compatible with the hypothesis that the new particle is the Standard Model Higgs boson, more data are needed to assess its nature in detail.

Acknowledgements

The results reported in this paper would not have been possible without the outstanding performance of the LHC. We warmly thank CERN and the entire LHC exploitation team, including the operation, technical and infrastructure groups, and all the people who have contributed to the conception, design and construction of this superb accelerator We thank also the support staﬀ at our institutions without whose excellent contributions ATLAS could not have been successfully constructed or operated so eﬃciently.

We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; EPLANET and ERC, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNAS, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT, Greece; ISF, MINERVA, GIF, DIP and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; RCN, Norway; MNiSW, Poland; GRICES and FCT, Portugal; MERYS (MECTS), Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MVZT, Slovenia; DST/NRF, South Africa; MICINN, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Leverhulme Trust, United Kingdom; DOE and NSF, United States of America.

The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN and the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CCIN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA) and in the Tier-2 facilities worldwide.

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The ATLAS Collaboration

G. Aad⁴⁸, T. Abajyan²¹, B. Abbott¹¹¹, J. Abdallah¹², S. Abdel Khalek¹¹⁵, A.A. Abdelalim⁴⁹, O. Abdinov¹¹,

R. Aben¹⁰⁵, B. Abi¹¹², M. Abolins⁸⁸, O.S. AbouZeid¹⁵⁸, H. Abramowicz¹⁵³, H. Abreu¹³⁶, B.S. Acharya^{^164a^,^164b},

L. Adamczyk³⁸, D.L. Adams²⁵, T.N. Addy⁵⁶, J. Adelman¹⁷⁶, S. Adomeit⁹⁸, P. Adragna⁷⁵, T. Adye¹²⁹, S. Aefsky²³,

J.A.: Aguilar-Saavedra^{^124b^,^a}, M. Agustoni¹⁷, M. Aharrouche⁸¹, S.P. Ahlen²², F. Ahles⁴⁸, A. Ahmad¹⁴⁸, M. Ahsan⁴¹,
G.: Aielli^{^133a^,^133b}, T. Akdogan^19a, T.P.A. Åkesson⁷⁹, G. Akimoto¹⁵⁵, A.V. Akimov⁹⁴, M.S. Alam², M.A. Alam⁷⁶,
J.: Albert¹⁶⁹, S. Albrand⁵⁵, M. Aleksa³⁰, I.N. Aleksandrov⁶⁴, F. Alessandria^89a, C. Alexa^26a, G. Alexander¹⁵³,
G.: Alexandre⁴⁹, T. Alexopoulos¹⁰, M. Alhroob^{^164a^,^164c}, M. Aliev¹⁶, G. Alimonti^89a, J. Alison¹²⁰,

B.M.M.: Allbrooke¹⁸, P.P. Allport⁷³, S.E. Allwood-Spiers⁵³, J. Almond⁸², A. Aloisio^{^102a^,^102b}, R. Alon¹⁷²,
A.: Alonso⁷⁹, F. Alonso⁷⁰, A. Altheimer³⁵, B. Alvarez Gonzalez⁸⁸, M.G. Alviggi^{^102a^,^102b}, K. Amako⁶⁵, C. Amelung²³,

V.V.: Ammosov^{¹²⁸^,^∗}, S.P. Amor Dos Santos^124a, A. Amorim^{^124a^,^b}, N. Amram¹⁵³, C. Anastopoulos³⁰, L.S. Ancu¹⁷,
N.: Andari¹¹⁵, T. Andeen³⁵, C.F. Anders^58b, G. Anders^58a, K.J. Anderson³¹, A. Andreazza^{^89a^,^89b}, V. Andrei^58a, M-L. Andrieux⁵⁵, X.S. Anduaga⁷⁰, S. Angelidakis⁹, P. Anger⁴⁴, A. Angerami³⁵, F. Anghinolﬁ³⁰, A. Anisenkov¹⁰⁷,
N.: Anjos^124a, A. Annovi⁴⁷, A. Antonaki⁹, M. Antonelli⁴⁷, A. Antonov⁹⁶, J. Antos^144b, F. Anulli^132a, M. Aoki¹⁰¹,
S.: Aoun⁸³, L. Aperio Bella⁵, R. Apolle^{¹¹⁸^,^c}, G. Arabidze⁸⁸, I. Aracena¹⁴³, Y. Arai⁶⁵, A.T.H. Arce⁴⁵, S. Arfaoui¹⁴⁸, J-F. Arguin⁹³, E. Arik^{^19a^,^∗}, M. Arik^19a, A.J. Armbruster⁸⁷, O. Arnaez⁸¹, V. Arnal⁸⁰, C. Arnault¹¹⁵, A. Artamonov⁹⁵,
G.: Artoni^{^132a^,^132b}, D. Arutinov²¹, S. Asai¹⁵⁵, S. Ask²⁸, B. Åsman^{^146a^,^146b}, L. Asquith⁶, K. Assamagan²⁵,
A.: Astbury¹⁶⁹, M. Atkinson¹⁶⁵, B. Aubert⁵, E. Auge¹¹⁵, K. Augsten¹²⁷, M. Aurousseau^145a, G. Avolio¹⁶³,
R.: Avramidou¹⁰, D. Axen¹⁶⁸, G. Azuelos^{⁹³^,^d}, Y. Azuma¹⁵⁵, M.A. Baak³⁰, G. Baccaglioni^89a, C. Bacci^{^134a^,^134b},

A.M.: Bach¹⁵, H. Bachacou¹³⁶, K. Bachas³⁰, M. Backes⁴⁹, M. Backhaus²¹, J. Backus Mayes¹⁴³, E. Badescu^26a,
P.: Bagnaia^{^132a^,^132b}, S. Bahinipati³, Y. Bai^33a, D.C. Bailey¹⁵⁸, T. Bain¹⁵⁸, J.T. Baines¹²⁹, O.K. Baker¹⁷⁶, M.D. Baker²⁵,
S.: Baker⁷⁷, P. Balek¹²⁶, E. Banas³⁹, P. Banerjee⁹³, Sw. Banerjee¹⁷³, D. Banﬁ³⁰, A. Bangert¹⁵⁰, V. Bansal¹⁶⁹,

H.S.: Bansil¹⁸, L. Barak¹⁷², S.P. Baranov⁹⁴, A. Barbaro Galtieri¹⁵, T. Barber⁴⁸, E.L. Barberio⁸⁶, D. Barberis^{^50a^,^50b},
M.: Barbero²¹, D.Y. Bardin⁶⁴, T. Barillari⁹⁹, M. Barisonzi¹⁷⁵, T. Barklow¹⁴³, N. Barlow²⁸, B.M. Barnett¹²⁹,

R.M.: Barnett¹⁵, A. Baroncelli^134a, G. Barone⁴⁹, A.J. Barr¹¹⁸, F. Barreiro⁸⁰, J. Barreiro Guimar˜aes da Costa⁵⁷,
P.: Barrillon¹¹⁵, R. Bartoldus¹⁴³, A.E. Barton⁷¹, V. Bartsch¹⁴⁹, A. Basye¹⁶⁵, R.L. Bates⁵³, L. Batkova^144a,

J.R.: Batley²⁸, A. Battaglia¹⁷, M. Battistin³⁰, F. Bauer¹³⁶, H.S. Bawa^{¹⁴³^,^e}, S. Beale⁹⁸, T. Beau⁷⁸, P.H. Beauchemin¹⁶¹,
R.: Beccherle^50a, P. Bechtle²¹, H.P. Beck¹⁷, A.K. Becker¹⁷⁵, S. Becker⁹⁸, M. Beckingham¹³⁸, K.H. Becks¹⁷⁵,

A.J.: Beddall^19c, A. Beddall^19c, S. Bedikian¹⁷⁶, V.A. Bednyakov⁶⁴, C.P. Bee⁸³, L.J. Beemster¹⁰⁵, M. Begel²⁵,
S.: Behar Harpaz¹⁵², P.K. Behera⁶², M. Beimforde⁹⁹, C. Belanger-Champagne⁸⁵, P.J. Bell⁴⁹, W.H. Bell⁴⁹, G. Bella¹⁵³,
L.: Bellagamba^20a, M. Bellomo³⁰, A. Belloni⁵⁷, O. Beloborodova^{107, f}, K. Belotskiy⁹⁶, O. Beltramello³⁰,
O.: Benary¹⁵³, D. Benchekroun^135a, K. Bendtz^{^146a^,^146b}, N. Benekos¹⁶⁵, Y. Benhammou¹⁵³, E. Benhar Noccioli⁴⁹,

J.A.: Benitez Garcia^159b, D.P. Benjamin⁴⁵, M. Benoit¹¹⁵, J.R. Bensinger²³, K. Benslama¹³⁰, S. Bentvelsen¹⁰⁵,
D.: Berge³⁰, E. Bergeaas Kuutmann⁴², N. Berger⁵, F. Berghaus¹⁶⁹, E. Berglund¹⁰⁵, J. Beringer¹⁵, P. Bernat⁷⁷,
R.: Bernhard⁴⁸, C. Bernius²⁵, F.U. Bernlochner¹⁶⁹, T. Berry⁷⁶, C. Bertella⁸³, A. Bertin^{^20a^,^20b}, F. Bertolucci^{^122a^,^122b},

M.I.: Besana^{^89a^,^89b}, G.J. Besjes¹⁰⁴, N. Besson¹³⁶, S. Bethke⁹⁹, W. Bhimji⁴⁶, R.M. Bianchi³⁰, M. Bianco^{^72a^,^72b},
O.: Biebel⁹⁸, S.P. Bieniek⁷⁷, K. Bierwagen⁵⁴, J. Biesiada¹⁵, M. Biglietti^134a, H. Bilokon⁴⁷, M. Bindi^{^20a^,^20b}, S. Binet¹¹⁵,
A.: Bingul^19c, C. Bini^{^132a^,^132b}, C. Biscarat¹⁷⁸, B. Bittner⁹⁹, K.M. Black²², R.E. Blair⁶, J.-B. Blanchard¹³⁶,
G.: Blanchot³⁰, T. Blazek^144a, I. Bloch⁴², C. Blocker²³, J. Blocki³⁹, A. Blondel⁴⁹, W. Blum⁸¹, U. Blumenschein⁵⁴,

G.J.: Bobbink¹⁰⁵, V.B. Bobrovnikov¹⁰⁷, S.S. Bocchetta⁷⁹, A. Bocci⁴⁵, C.R. Boddy¹¹⁸, M. Boehler⁴⁸, J. Boek¹⁷⁵,
N.: Boelaert³⁶, J.A. Bogaerts³⁰, A. Bogdanchikov¹⁰⁷, A. Bogouch^{⁹⁰^,^∗}, C. Bohm^146a, J. Bohm¹²⁵, V. Boisvert⁷⁶,
T.: Bold³⁸, V. Boldea^26a, N.M. Bolnet¹³⁶, M. Bomben⁷⁸, M. Bona⁷⁵, M. Boonekamp¹³⁶, S. Bordoni⁷⁸, C. Borer¹⁷,
A.: Borisov¹²⁸, G. Borissov⁷¹, I. Borjanovic^13a, M. Borri⁸², S. Borroni⁸⁷, V. Bortolotto^{^134a^,^134b}, K. Bos¹⁰⁵,
D.: Boscherini^20a, M. Bosman¹², H. Boterenbrood¹⁰⁵, J. Bouchami⁹³, J. Boudreau¹²³, E.V. Bouhova-Thacker⁷¹,
D.: Boumediene³⁴, C. Bourdarios¹¹⁵, N. Bousson⁸³, A. Boveia³¹, J. Boyd³⁰, I.R. Boyko⁶⁴, I. Bozovic-Jelisavcic^13b,
J.: Bracinik¹⁸, P. Branchini^134a, G.W. Brandenburg⁵⁷, A. Brandt⁸, G. Brandt¹¹⁸, O. Brandt⁵⁴, U. Bratzler¹⁵⁶, B. Brau⁸⁴,

J.E.: Brau¹¹⁴, H.M. Braun^{¹⁷⁵^,^∗}, S.F. Brazzale^{^164a^,^164c}, B. Brelier¹⁵⁸, J. Bremer³⁰, K. Brendlinger¹²⁰, R. Brenner¹⁶⁶,
S.: Bressler¹⁷², D. Britton⁵³, F.M. Brochu²⁸, I. Brock²¹, R. Brock⁸⁸, F. Broggi^89a, C. Bromberg⁸⁸, J. Bronner⁹⁹,
G.: Brooijmans³⁵, T. Brooks⁷⁶, W.K. Brooks^32b, G. Brown⁸², H. Brown⁸, P.A. Bruckman de Renstrom³⁹,
D.: Bruncko^144b, R. Bruneliere⁴⁸, S. Brunet⁶⁰, A. Bruni^20a, G. Bruni^20a, M. Bruschi^20a, T. Buanes¹⁴, Q. Buat⁵⁵,
F.: Bucci⁴⁹, J. Buchanan¹¹⁸, P. Buchholz¹⁴¹, R.M. Buckingham¹¹⁸, A.G. Buckley⁴⁶, S.I. Buda^26a, I.A. Budagov⁶⁴,
B.: Budick¹⁰⁸, V. B¨uscher⁸¹, L. Bugge¹¹⁷, O. Bulekov⁹⁶, A.C. Bundock⁷³, M. Bunse⁴³, T. Buran¹¹⁷, H. Burckhart³⁰,
S.: Burdin⁷³, T. Burgess¹⁴, S. Burke¹²⁹, E. Busato³⁴, P. Bussey⁵³, C.P. Buszello¹⁶⁶, B. Butler¹⁴³, J.M. Butler²²,

C.M.: Buttar⁵³, J.M. Butterworth⁷⁷, W. Buttinger²⁸, S. Cabrera Urban´¹⁶⁷, D. Caforio^{^20a^,^20b}, O. Cakir^4a, P. Calaﬁura¹⁵,
G.: Calderini⁷⁸, P. Calfayan⁹⁸, R. Calkins¹⁰⁶, L.P. Caloba^24a, R. Caloi^{^132a^,^132b}, D. Calvet³⁴, S. Calvet³⁴,
R.: Camacho Toro³⁴, P. Camarri^{^133a^,^133b}, D. Cameron¹¹⁷, L.M. Caminada¹⁵, R. Caminal Armadans¹², S. Campana³⁰,
M.: Campanelli⁷⁷, V. Canale^{^102a^,^102b}, F. Canelli^{³¹^,^g}, A. Canepa^159a, J. Cantero⁸⁰, R. Cantrill⁷⁶, L. Capasso^{^102a^,^102b},

M.D.M.: Capeans Garrido³⁰, I. Caprini^26a, M. Caprini^26a, D. Capriotti⁹⁹, M. Capua^{^37a^,^37b}, R. Caputo⁸¹,
R.: Cardarelli^133a, T. Carli³⁰, G. Carlino^102a, L. Carminati^{^89a^,^89b}, B. Caron⁸⁵, S. Caron¹⁰⁴, E. Carquin^32b,

G.D.: Carrillo Montoya¹⁷³, A.A. Carter⁷⁵, J.R. Carter²⁸, J. Carvalho^{^124a^,^h}, D. Casadei¹⁰⁸, M.P. Casado¹²,
M.: Cascella^{^122a^,^122b}, C. Caso^{^50a^,^50b^,^∗}, A.M. Castaneda Hernandez^{¹⁷³^,ⁱ}, E. Castaneda-Miranda¹⁷³,
V.: Castillo Gimenez¹⁶⁷, N.F. Castro^124a, G. Cataldi^72a, P. Catastini⁵⁷, A. Catinaccio³⁰, J.R. Catmore³⁰, A. Cattai³⁰,
G.: Cattani^{^133a^,^133b}, S. Caughron⁸⁸, V. Cavaliere¹⁶⁵, P. Cavalleri⁷⁸, D. Cavalli^89a, M. Cavalli-Sforza¹²,
V.: Cavasinni^{^122a^,^122b}, F. Ceradini^{^134a^,^134b}, A.S. Cerqueira^24b, A. Cerri³⁰, L. Cerrito⁷⁵, F. Cerutti⁴⁷, S.A. Cetin^19b,
A.: Chafaq^135a, D. Chakraborty¹⁰⁶, I. Chalupkova¹²⁶, K. Chan³, P. Chang¹⁶⁵, B. Chapleau⁸⁵, J.D. Chapman²⁸,

J.W.: Chapman⁸⁷, E. Chareyre⁷⁸, D.G. Charlton¹⁸, V. Chavda⁸², C.A. Chavez Barajas³⁰, S. Cheatham⁸⁵,
S.: Chekanov⁶, S.V. Chekulaev^159a, G.A. Chelkov⁶⁴, M.A. Chelstowska¹⁰⁴, C. Chen⁶³, H. Chen²⁵, S. Chen^33c,
X.: Chen¹⁷³, Y. Chen³⁵, Y. Cheng³¹, A. Cheplakov⁶⁴, R. Cherkaoui El Moursli^135e, V. Chernyatin²⁵, E. Cheu⁷,

S.L.: Cheung¹⁵⁸, L. Chevalier¹³⁶, G. Chiefari^{^102a^,^102b}, L. Chikovani^{^51a^,^∗}, J.T. Childers³⁰, A. Chilingarov⁷¹,
G.: Chiodini^72a, A.S. Chisholm¹⁸, R.T. Chislett⁷⁷, A. Chitan^26a, M.V. Chizhov⁶⁴, G. Choudalakis³¹, S. Chouridou¹³⁷,

I.A. Christidi⁷⁷, A. Christov⁴⁸, D. Chromek-Burckhart³⁰, M.L. Chu¹⁵¹, J. Chudoba¹²⁵, G. Ciapetti^{^132a^,^132b},

A.K. Ciftci^4a, R. Ciftci^4a, D. Cinca³⁴, V. Cindro⁷⁴, C. Ciocca^{^20a^,^20b}, A. Ciocio¹⁵, M. Cirilli⁸⁷, P. Cirkovic^13b,

Z.H. Citron¹⁷², M. Citterio^89a, M. Ciubancan^26a, A. Clark⁴⁹, P.J. Clark⁴⁶, R.N. Clarke¹⁵, W. Cleland¹²³,

J.C.: Clemens⁸³, B. Clement⁵⁵, C. Clement^{^146a^,^146b}, Y. Coadou⁸³, M. Cobal^{^164a^,^164c}, A. Coccaro¹³⁸, J. Cochran⁶³,
L.: Coﬀey²³, J.G. Cogan¹⁴³, J. Coggeshall¹⁶⁵, E. Cogneras¹⁷⁸, J. Colas⁵, S. Cole¹⁰⁶, A.P. Colijn¹⁰⁵, N.J. Collins¹⁸,

124a

C. Collins-Tooth⁵³, J. Collot⁵⁵, T. Colombo^{^119a^,^119b}, G. Colon⁸⁴, G. Compostella⁹⁹, P. Conde Mui˜no,

E. Coniavitis¹⁶⁶, M.C. Conidi¹², S.M. Consonni^{^89a^,^89b}, V. Consorti⁴⁸, S. Constantinescu^26a, C. Conta^{^119a^,^119b},

G. Conti⁵⁷, F. Conventi^{102a, j}, M. Cooke¹⁵, B.D. Cooper⁷⁷, A.M. Cooper-Sarkar¹¹⁸, N.J. Cooper-Smith⁷⁶, K. Copic¹⁵,

T. Cornelissen¹⁷⁵, M. Corradi^20a, F. Corriveau^{⁸⁵^,^k}, A. Cortes-Gonzalez¹⁶⁵, G. Cortiana⁹⁹, G. Costa^89a, M.J. Costa¹⁶⁷,

D. Costanzo¹³⁹, D. Cotˆe´³⁰, L. Courneyea¹⁶⁹, G. Cowan⁷⁶, C. Cowden²⁸, B.E. Cox⁸², K. Cranmer¹⁰⁸,

F. Crescioli^{^122a^,^122b}, M. Cristinziani²¹, G. Crosetti^{^37a^,^37b}, S. Cr´ep´e-Renaudin⁵⁵, C.-M. Cuciuc^26a,

C. Cuenca Almenar¹⁷⁶, T. Cuhadar Donszelmann¹³⁹, M. Curatolo⁴⁷, C.J. Curtis¹⁸, C. Cuthbert¹⁵⁰, P. Cwetanski⁶⁰,

H. Czirr¹⁴¹, P. Czodrowski⁴⁴, Z. Czyczula¹⁷⁶, S. D’Auria⁵³, M. D’Onofrio⁷³, A. D’Orazio^{^132a^,^132b},

M.J.: Da Cunha Sargedas De Sousa^124a, C. Da Via⁸², W. Dabrowski³⁸, A. Daﬁnca¹¹⁸, T. Dai⁸⁷, C. Dallapiccola⁸⁴,
M.: Dam³⁶, M. Dameri^{^50a^,^50b}, D.S. Damiani¹³⁷, H.O. Danielsson³⁰, V. Dao⁴⁹, G. Darbo^50a, G.L. Darlea^26b,

J.A.: Dassoulas⁴², W. Davey²¹, T. Davidek¹²⁶, N. Davidson⁸⁶, R. Davidson⁷¹, E. Davies^{¹¹⁸^,^c}, M. Davies⁹³,
O.: Davignon⁷⁸, A.R. Davison⁷⁷, Y. Davygora^58a, E. Dawe¹⁴², I. Dawson¹³⁹, R.K. Daya-Ishmukhametova²³, K. De⁸,
R.: de Asmundis^102a, S. De Castro^{^20a^,^20b}, S. De Cecco⁷⁸, J. de Graat⁹⁸, N. De Groot¹⁰⁴, P. de Jong¹⁰⁵,
C.: De La Taille¹¹⁵, H. De la Torre⁸⁰, F. De Lorenzi⁶³, L. de Mora⁷¹, L. De Nooij¹⁰⁵, D. De Pedis^132a, A. De Salvo^132a,
U.: De Sanctis^{^164a^,^164c}, A. De Santo¹⁴⁹, J.B. De Vivie De Regie¹¹⁵, G. De Zorzi^{^132a^,^132b}, W.J. Dearnaley⁷¹, R. Debbe²⁵,
C.: Debenedetti⁴⁶, B. Dechenaux⁵⁵, D.V. Dedovich⁶⁴, J. Degenhardt¹²⁰, C. Del Papa^{^164a^,^164c}, J. Del Peso⁸⁰,
T.: Del Prete^{^122a^,^122b}, T. Delemontex⁵⁵, M. Deliyergiyev⁷⁴, A. Dell’Acqua³⁰, L. Dell’Asta²², M. Della Pietra^{102a, j},
D.: della Volpe^{^102a^,^102b}, M. Delmastro⁵, P. Delpierre⁸³, P.A. Delsart⁵⁵, C. Deluca¹⁰⁵, S. Demers¹⁷⁶, M. Demichev⁶⁴,
B.: Demirkoz^{¹²^,^l}, J. Deng¹⁶³, S.P. Denisov¹²⁸, D. Derendarz³⁹, J.E. Derkaoui^135d, F. Derue⁷⁸, P. Dervan⁷³, K. Desch²¹,
E.: Devetak¹⁴⁸, P.O. Deviveiros¹⁰⁵, A. Dewhurst¹²⁹, B. DeWilde¹⁴⁸, S. Dhaliwal¹⁵⁸, R. Dhullipudi^{²⁵^,^m},
A.: Di Ciaccio^{^133a^,^133b}, L. Di Ciaccio⁵, C. Di Donato^{^102a^,^102b}, A. Di Girolamo³⁰, B. Di Girolamo³⁰,
S.: Di Luise^{^134a^,^134b}, A. Di Mattia¹⁷³, B. Di Micco³⁰, R. Di Nardo⁴⁷, A. Di Simone^{^133a^,^133b}, R. Di Sipio^{^20a^,^20b},

M.A.: Diaz^32a, E.B. Diehl⁸⁷, J. Dietrich⁴², T.A. Dietzsch^58a, S. Diglio⁸⁶, K. Dindar Yagci⁴⁰, J. Dingfelder²¹,
F.: Dinut^26a, C. Dionisi^{^132a^,^132b}, P. Dita^26a, S. Dita^26a, F. Dittus³⁰, F. Djama⁸³, T. Djobava^51b, M.A.B. do Vale^24c,
A.: Do Valle Wemans^{^124a^,ⁿ}, T.K.O. Doan⁵, M. Dobbs⁸⁵, R. Dobinson^{³⁰^,^∗}, D. Dobos³⁰, E. Dobson^{³⁰^,^o}, J. Dodd³⁵,
C.: Doglioni⁴⁹, T. Doherty⁵³, Y. Doi^{⁶⁵^,^∗}, J. Dolejsi¹²⁶, I. Dolenc⁷⁴, Z. Dolezal¹²⁶, B.A. Dolgoshein^{⁹⁶^,^∗}, T. Dohmae¹⁵⁵,
M.: Donadelli^24d, J. Donini³⁴, J. Dopke³⁰, A. Doria^102a, A. Dos Anjos¹⁷³, A. Dotti^{^122a^,^122b}, M.T. Dova⁷⁰,

J.D.: Dowell¹⁸, A.D. Doxiadis¹⁰⁵, A.T. Doyle⁵³, N. Dressnandt¹²⁰, M. Dris¹⁰, J. Dubbert⁹⁹, S. Dube¹⁵,
E.: Duchovni¹⁷², G. Duckeck⁹⁸, D. Duda¹⁷⁵, A. Dudarev³⁰, F. Dudziak⁶³, M. D¨uhrssen³⁰, I.P. Duerdoth⁸²,
L.: Duﬂot¹¹⁵, M-A. Dufour⁸⁵, L. Duguid⁷⁶, M. Dunford^58a, H. Duran Yildiz^4a, R. Duxﬁeld¹³⁹, M. Dwuznik³⁸,
F.: Dydak³⁰, M. Duren¨⁵², W.L. Ebenstein⁴⁵, J. Ebke⁹⁸, S. Eckweiler⁸¹, K. Edmonds⁸¹, W. Edson², C.A. Edwards⁷⁶,

N.C.: Edwards⁵³, W. Ehrenfeld⁴², T. Eifert¹⁴³, G. Eigen¹⁴, K. Einsweiler¹⁵, E. Eisenhandler⁷⁵, T. Ekelof¹⁶⁶,
M.: El Kacimi^135c, M. Ellert¹⁶⁶, S. Elles⁵, F. Ellinghaus⁸¹, K. Ellis⁷⁵, N. Ellis³⁰, J. Elmsheuser⁹⁸, M. Elsing³⁰,
D.: Emeliyanov¹²⁹, R. Engelmann¹⁴⁸, A. Engl⁹⁸, B. Epp⁶¹, J. Erdmann⁵⁴, A. Ereditato¹⁷, D. Eriksson^146a, J. Ernst²,
M.: Ernst²⁵, J. Ernwein¹³⁶, D. Errede¹⁶⁵, S. Errede¹⁶⁵, E. Ertel⁸¹, M. Escalier¹¹⁵, H. Esch⁴³, C. Escobar¹²³,
X.: Espinal Curull¹², B. Esposito⁴⁷, F. Etienne⁸³, A.I. Etienvre¹³⁶, E. Etzion¹⁵³, D. Evangelakou⁵⁴, H. Evans⁶⁰,
L.: Fabbri^{^20a^,^20b}, C. Fabre³⁰, R.M. Fakhrutdinov¹²⁸, S. Falciano^132a, Y. Fang¹⁷³, M. Fanti^{^89a^,^89b}, A. Farbin⁸,
A.: Farilla^134a, J. Farley¹⁴⁸, T. Farooque¹⁵⁸, S. Farrell¹⁶³, S.M. Farrington¹⁷⁰, P. Farthouat³⁰, F. Fassi¹⁶⁷,
P.: Fassnacht³⁰, D. Fassouliotis⁹, B. Fatholahzadeh¹⁵⁸, A. Favareto^{^89a^,^89b}, L. Fayard¹¹⁵, S. Fazio^{^37a^,^37b}, R. Febbraro³⁴,
P.: Federic^144a, O.L. Fedin¹²¹, W. Fedorko⁸⁸, M. Fehling-Kaschek⁴⁸, L. Feligioni⁸³, D. Fellmann⁶, C. Feng^33d,

E.J.: Feng⁶, A.B. Fenyuk¹²⁸, J. Ferencei^144b, W. Fernando⁶, S. Ferrag⁵³, J. Ferrando⁵³, V. Ferrara⁴², A. Ferrari¹⁶⁶,
P.: Ferrari¹⁰⁵, R. Ferrari^119a, D.E. Ferreira de Lima⁵³, A. Ferrer¹⁶⁷, D. Ferrere⁴⁹, C. Ferretti⁸⁷, A. Ferretto Parodi^{^50a^,^50b},
M.: Fiascaris³¹, F. Fiedler⁸¹, A. Filipˇciˇc⁷⁴, F. Filthaut¹⁰⁴, M. Fincke-Keeler¹⁶⁹, M.C.N. Fiolhais^{^124a^,^h}, L. Fiorini¹⁶⁷,
A.: Firan⁴⁰, G. Fischer⁴², M.J. Fisher¹⁰⁹, M. Flechl⁴⁸, I. Fleck¹⁴¹, J. Fleckner⁸¹, P. Fleischmann¹⁷⁴, S. Fleischmann¹⁷⁵,
T.: Flick¹⁷⁵, A. Floderus⁷⁹, L.R. Flores Castillo¹⁷³, M.J. Flowerdew⁹⁹, T. Fonseca Martin¹⁷, A. Formica¹³⁶, A. Forti⁸²,
D.: Fortin^159a, D. Fournier¹¹⁵, A.J. Fowler⁴⁵, H. Fox⁷¹, P. Francavilla¹², M. Franchini^{^20a^,^20b}, S. Franchino^{^119a^,^119b},
D.: Francis³⁰, T. Frank¹⁷², M. Franklin⁵⁷, S. Franz³⁰, M. Fraternali^{^119a^,^119b}, S. Fratina¹²⁰, S.T. French²⁸,
C.: Friedrich⁴², F. Friedrich⁴⁴, R. Froeschl³⁰, D. Froidevaux³⁰, J.A. Frost²⁸, C. Fukunaga¹⁵⁶, E. Fullana Torregrosa³⁰,

B.G.: Fulsom¹⁴³, J. Fuster¹⁶⁷, C. Gabaldon³⁰, O. Gabizon¹⁷², S. Gadatsch¹⁰⁵, T. Gadfort²⁵, S. Gadomski⁴⁹,
G.: Gagliardi^{^50a^,^50b}, P. Gagnon⁶⁰, C. Galea⁹⁸, B. Galhardo^124a, E.J. Gallas¹¹⁸, V. Gallo¹⁷, B.J. Gallop¹²⁹, P. Gallus¹²⁵,

K.K.: Gan¹⁰⁹, Y.S. Gao^{¹⁴³^,^e}, A. Gaponenko¹⁵, F. Garberson¹⁷⁶, M. Garcia-Sciveres¹⁵, C. Garc´ıa¹⁶⁷, J.E. Garc´ıa Navarro¹⁶⁷, R.W. Gardner³¹, N. Garelli³⁰, H. Garitaonandia¹⁰⁵, V. Garonne³⁰, C. Gatti⁴⁷, G. Gaudio^119a, B. Gaur¹⁴¹,
L.: Gauthier¹³⁶, P. Gauzzi^{^132a^,^132b}, I.L. Gavrilenko⁹⁴, C. Gay¹⁶⁸, G. Gaycken²¹, E.N. Gazis¹⁰, P. Ge^33d, Z. Gecse¹⁶⁸,

C.N.P. Gee¹²⁹, D.A.A. Geerts¹⁰⁵, Ch. Geich-Gimbel²¹, K. Gellerstedt^{^146a^,^146b}, C. Gemme^50a, A. Gemmell⁵³,

M.H.: Genest⁵⁵, S. Gentile^{^132a^,^132b}, M. George⁵⁴, S. George⁷⁶, P. Gerlach¹⁷⁵, A. Gershon¹⁵³, C. Geweniger^58a,
H.: Ghazlane^135b, N. Ghodbane³⁴, B. Giacobbe^20a, S. Giagu^{^132a^,^132b}, V. Giakoumopoulou⁹, V. Giangiobbe¹²,
F.: Gianotti³⁰, B. Gibbard²⁵, A. Gibson¹⁵⁸, S.M. Gibson³⁰, M. Gilchriese¹⁵, O. Gildemeister³⁰, D. Gillberg²⁹,

A.R. Gillman¹²⁹, D.M. Gingrich^{³^,^d}, J. Ginzburg¹⁵³, N. Giokaris⁹, M.P. Giordani^164c, R. Giordano^{^102a^,^102b},

F.M. Giorgi¹⁶, P. Giovannini⁹⁹, P.F. Giraud¹³⁶, D. Giugni^89a, M. Giunta⁹³, P. Giusti^20a, B.K. Gjelsten¹¹⁷,

L.K.: Gladilin⁹⁷, C. Glasman⁸⁰, J. Glatzer²¹, A. Glazov⁴², K.W. Glitza¹⁷⁵, G.L. Glonti⁶⁴, J.R. Goddard⁷⁵,
J.: Godfrey¹⁴², J. Godlewski³⁰, M. Goebel⁴², T. G¨opfert⁴⁴, C. Goeringer⁸¹, C. G¨ossling⁴³, S. Goldfarb⁸⁷,
T.: Golling¹⁷⁶, A. Gomes^{^124a^,^b}, L.S. Gomez Fajardo⁴², R. Gonc¸alo⁷⁶, J. Goncalves Pinto Firmino Da Costa⁴²,
L.: Gonella²¹, S. Gonz´,

alez de la Hoz¹⁶⁷, G. Gonzalez Parra¹², M.L. Gonzalez Silva²⁷, S. Gonzalez-Sevilla⁴⁹

J.J.: Goodson¹⁴⁸, L. Goossens³⁰, P.A. Gorbounov⁹⁵, H.A. Gordon²⁵, I. Gorelov¹⁰³, G. Gorﬁne¹⁷⁵, B. Gorini³⁰,
E.: Gorini^{^72a^,^72b}, A. Gorisekˇ ⁷⁴, E. Gornicki³⁹, B. Gosdzik⁴², A.T. Goshaw⁶, M. Gosselink¹⁰⁵, M.I. Gostkin⁶⁴,
I.: Gough Eschrich¹⁶³, M. Gouighri^135a, D. Goujdami^135c, M.P. Goulette⁴⁹, A.G. Goussiou¹³⁸, C. Goy⁵, S. Gozpinar²³,
I.: Grabowska-Bold³⁸, P. Grafstr¨om^{^20a^,^20b}, K-J. Grahn⁴², E. Gramstad¹¹⁷, F. Grancagnolo^72a, S. Grancagnolo¹⁶,
V.: Grassi¹⁴⁸, V. Gratchev¹²¹, N. Grau³⁵, H.M. Gray³⁰, J.A. Gray¹⁴⁸, E. Graziani^134a, O.G. Grebenyuk¹²¹,
T.: Greenshaw⁷³, Z.D. Greenwood^{²⁵^,^m}, K. Gregersen³⁶, I.M. Gregor⁴², P. Grenier¹⁴³, J. Griﬃths⁸, N. Grigalashvili⁶⁴,

A.A.: Grillo¹³⁷, S. Grinstein¹², Ph. Gris³⁴, Y.V. Grishkevich⁹⁷, J.-F. Grivaz¹¹⁵, E. Gross¹⁷², J. Grosse-Knetter⁵⁴,
J.: Groth-Jensen¹⁷², K. Grybel¹⁴¹, D. Guest¹⁷⁶, C. Guicheney³⁴, T. Guillemin¹¹⁵, S. Guindon⁵⁴, U. Gul⁵³,
J.: Gunther¹²⁵, B. Guo¹⁵⁸, J. Guo³⁵, P. Gutierrez¹¹¹, N. Guttman¹⁵³, O. Gutzwiller¹⁷³, C. Guyot¹³⁶, C. Gwenlan¹¹⁸,

C.B.: Gwilliam⁷³, A. Haas¹⁴³, S. Haas³⁰, C. Haber¹⁵, H.K. Hadavand⁴⁰, D.R. Hadley¹⁸, P. Haefner²¹, F. Hahn³⁰,
S.: Haider³⁰, Z. Hajduk³⁹, H. Hakobyan¹⁷⁷, D. Hall¹¹⁸, K. Hamacher¹⁷⁵, P. Hamal¹¹³, K. Hamano⁸⁶, M. Hamer⁵⁴,
A.: Hamilton^{^145b^,^p}, S. Hamilton¹⁶¹, L. Han^33b, K. Hanagaki¹¹⁶, K. Hanawa¹⁶⁰, M. Hance¹⁵, C. Handel⁸¹, P. Hanke^58a,

J.R.: Hansen³⁶, J.B. Hansen³⁶, J.D. Hansen³⁶, P.H. Hansen³⁶, P. Hansson¹⁴³, K. Hara¹⁶⁰, A.S. Hard¹⁷³, G.A. Hare¹³⁷,
T.: Harenberg¹⁷⁵, S. Harkusha⁹⁰, D. Harper⁸⁷, R.D. Harrington⁴⁶, O.M. Harris¹³⁸, J. Hartert⁴⁸, F. Hartjes¹⁰⁵,
T.: Haruyama⁶⁵, A. Harvey⁵⁶, S. Hasegawa¹⁰¹, Y. Hasegawa¹⁴⁰, S. Hassani¹³⁶, S. Haug¹⁷, M. Hauschild³⁰,
R.: Hauser⁸⁸, M. Havranek²¹, C.M. Hawkes¹⁸, R.J. Hawkings³⁰, A.D. Hawkins⁷⁹, T. Hayakawa⁶⁶, T. Hayashi¹⁶⁰,
D.: Hayden⁷⁶, C.P. Hays¹¹⁸, H.S. Hayward⁷³, S.J. Haywood¹²⁹, S.J. Head¹⁸, V. Hedberg⁷⁹, L. Heelan⁸, S. Heim⁸⁸,
B.: Heinemann¹⁵, S. Heisterkamp³⁶, L. Helary²², C. Heller⁹⁸, M. Heller³⁰, S. Hellman^{^146a^,^146b}, D. Hellmich²¹,
C.: Helsens¹², R.C.W. Henderson⁷¹, M. Henke^58a, A. Henrichs⁵⁴, A.M. Henriques Correia³⁰, S. Henrot-Versille¹¹⁵,
C.: Hensel⁵⁴, T. Henß¹⁷⁵, C.M. Hernandez⁸, Y. Hern´enez¹⁶⁷, R. Herrberg¹⁶, G. Herten⁴⁸, R. Hertenberger⁹⁸

andez Jim´,

L. Hervas³⁰, G.G. Hesketh⁷⁷, N.P. Hessey¹⁰⁵, E. Hig´on-Rodriguez¹⁶⁷, J.C. Hill²⁸, K.H. Hiller⁴², S. Hillert²¹,

S.J. Hillier¹⁸, I. Hinchliﬀe¹⁵, E. Hines¹²⁰, M. Hirose¹¹⁶, F. Hirsch⁴³, D. Hirschbuehl¹⁷⁵, J. Hobbs¹⁴⁸, N. Hod¹⁵³,

M.C.: Hodgkinson¹³⁹, P. Hodgson¹³⁹, A. Hoecker³⁰, M.R. Hoeferkamp¹⁰³, J. Hoﬀman⁴⁰, D. Hoﬀmann,
M.: Hohlfeld⁸¹, M. Holder¹⁴¹, S.O. Holmgren^146a, T. Holy¹²⁷, J.L. Holzbauer⁸⁸, T.M. Hong¹²⁰,
L.: Hooft van Huysduynen¹⁰⁸, S. Horner⁴⁸, J-Y. Hostachy⁵⁵, S. Hou¹⁵¹, A. Hoummada^135a, J. Howard¹¹⁸,
J.: Howarth⁸², I. Hristova¹⁶, J. Hrivnac¹¹⁵, T. Hryn’ova⁵, P.J. Hsu⁸¹, S.-C. Hsu¹⁵, D. Hu³⁵, Z. Hubacek¹²⁷,
F.: Hubaut⁸³, F. Huegging²¹, A. Huettmann⁴², T.B. Huﬀman¹¹⁸, E.W. Hughes³⁵, G. Hughes⁷¹, M. Huhtinen³⁰,
M.: Hurwitz¹⁵, N. Huseynov^{⁶⁴^,^q}, J. Huston⁸⁸, J. Huth⁵⁷, G. Iacobucci⁴⁹, G. Iakovidis¹⁰, M. Ibbotson⁸²,
I.: Ibragimov¹⁴¹, L. Iconomidou-Fayard¹¹⁵, J. Idarraga¹¹⁵, P. Iengo^102a, O. Igonkina¹⁰⁵, Y. Ikegami⁶⁵, M. Ikeno⁶⁵,
D.: Iliadis¹⁵⁴, N. Ilic¹⁵⁸, T. Ince⁹⁹, J. Inigo-Golﬁn³⁰, P. Ioannou⁹, M. Iodice^134a, K. Iordanidou⁹, V. Ippolito^{^132a^,^132b},
A.: Irles Quiles¹⁶⁷, C. Isaksson¹⁶⁶, M. Ishino⁶⁷, M. Ishitsuka¹⁵⁷, R. Ishmukhametov¹⁰⁹, C. Issever¹¹⁸, S. Istin^19a,

A.V. Ivashin¹²⁸, W. Iwanski³⁹, H. Iwasaki⁶⁵, J.M. Izen⁴¹, V. Izzo^102a, B. Jackson¹²⁰, J.N. Jackson⁷³, P. Jackson¹,

M.R.: Jaekel³⁰, V. Jain⁶⁰, K. Jakobs⁴⁸, S. Jakobsen³⁶, T. Jakoubek¹²⁵, J. Jakubek¹²⁷, D.O. Jamin¹⁵¹, D.K. Jana¹¹¹,
E.: Jansen⁷⁷, H. Jansen³⁰, A. Jantsch⁹⁹, M. Janus⁴⁸, G. Jarlskog⁷⁹, L. Jeanty⁵⁷, I. Jen-La Plante³¹, D. Jennens⁸⁶,
P.: Jenni³⁰, A.E. Loevschall-Jensen³⁶, P. Jeˇz³⁶, S. J´ez´equel⁵, M.K. Jha^20a, H. Ji¹⁷³, W. Ji⁸¹, J. Jia¹⁴⁸, Y. Jiang^33b,
M.: Jimenez Belenguer⁴², S. Jin^33a, O. Jinnouchi¹⁵⁷, M.D. Joergensen³⁶, D. Joﬀe⁴⁰, M. Johansen^{^146a^,^146b},

K.E. Johansson^146a, P. Johansson¹³⁹, S. Johnert⁴², K.A. Johns⁷, K. Jon-And^{^146a^,^146b}, G. Jones¹⁷⁰, R.W.L. Jones⁷¹,

T.J. Jones⁷³, C. Joram³⁰, P.M. Jorge^124a, K.D. Joshi⁸², J. Jovicevic¹⁴⁷, T. Jovin^13b, X. Ju¹⁷³, C.A. Jung⁴³,

R.M.: Jungst³⁰, V. Juranek¹²⁵, P. Jussel⁶¹, A. Juste Rozas¹², S. Kabana¹⁷, M. Kaci¹⁶⁷, A. Kaczmarska³⁹, P. Kadlecik³⁶,
M.: Kado¹¹⁵, H. Kagan¹⁰⁹, M. Kagan⁵⁷, E. Kajomovitz¹⁵², S. Kalinin¹⁷⁵, L.V. Kalinovskaya⁶⁴, S. Kama⁴⁰,
N.: Kanaya¹⁵⁵, M. Kaneda³⁰, S. Kaneti²⁸, T. Kanno¹⁵⁷, V.A. Kantserov⁹⁶, J. Kanzaki⁶⁵, B. Kaplan¹⁰⁸, A. Kapliy³¹,
J.: Kaplon³⁰, D. Kar⁵³, M. Karagounis²¹, K. Karakostas¹⁰, M. Karnevskiy⁴², V. Kartvelishvili⁷¹, A.N. Karyukhin¹²⁸,
L.: Kashif¹⁷³, G. Kasieczka^58b, R.D. Kass¹⁰⁹, A. Kastanas¹⁴, M. Kataoka⁵, Y. Kataoka¹⁵⁵, E. Katsouﬁs¹⁰, J. Katzy⁴²,
V.: Kaushik⁷, K. Kawagoe⁶⁹, T. Kawamoto¹⁵⁵, G. Kawamura⁸¹, M.S. Kayl¹⁰⁵, S. Kazama¹⁵⁵, V.A. Kazanin¹⁰⁷,

M.Y.: Kazarinov⁶⁴, R. Keeler¹⁶⁹, P.T. Keener¹²⁰, R. Kehoe⁴⁰, M. Keil⁵⁴, G.D. Kekelidze⁶⁴, J.S. Keller¹³⁸,
M.: Kenyon⁵³, O. Kepka¹²⁵, N. Kerschen³⁰, B.P. Kersevanˇ⁷⁴, S. Kersten¹⁷⁵, K. Kessoku¹⁵⁵, J. Keung¹⁵⁸,
F.: Khalil-zada¹¹, H. Khandanyan^{^146a^,^146b}, A. Khanov¹¹², D. Kharchenko⁶⁴, A. Khodinov⁹⁶, A. Khomich^58a,

T.J. Khoo²⁸, G. Khoriauli²¹, A. Khoroshilov¹⁷⁵, V. Khovanskiy⁹⁵, E. Khramov⁶⁴, J. Khubua^51b, H. Kim^{^146a^,^146b},

S.H.: Kim¹⁶⁰, N. Kimura¹⁷¹, O. Kind¹⁶, B.T. King⁷³, M. King⁶⁶, R.S.B. King¹¹⁸, J. Kirk¹²⁹, A.E. Kiryunin⁹⁹,
T.: Kishimoto⁶⁶, D. Kisielewska³⁸, T. Kitamura⁶⁶, T. Kittelmann¹²³, K. Kiuchi¹⁶⁰, E. Kladiva^144b, M. Klein⁷³,
U.: Klein⁷³, K. Kleinknecht⁸¹, M. Klemetti⁸⁵, A. Klier¹⁷², P. Klimek^{^146a^,^146b}, A. Klimentov²⁵, R. Klingenberg⁴³,

J.A.: Klinger⁸², E.B. Klinkby³⁶, T. Klioutchnikova³⁰, P.F. Klok¹⁰⁴, S. Klous¹⁰⁵, E.-E. Kluge^58a, T. Kluge⁷³, P. Kluit¹⁰⁵,
S.: Kluth⁹⁹, E. Kneringer⁶¹, E.B.F.G. Knoops⁸³, A. Knue⁵⁴, B.R. Ko⁴⁵, T. Kobayashi¹⁵⁵, M. Kobel⁴⁴, M. Kocian¹⁴³,

P. Kodys¹²⁶, K. K¨onig¹⁰⁴, S. Koenig⁸¹, L. K¨,

oneke³⁰, A.C. K¨opke⁸¹, F. Koetsveld¹⁰⁴, P. Koevesarki²¹, T. Koﬀas

E. Koﬀeman¹⁰⁵, L.A. Kogan¹¹⁸, S. Kohlmann¹⁷⁵, F. Kohn⁵⁴, Z. Kohout¹²⁷, T. Kohriki⁶⁵, T. Koi¹⁴³,

G.M.: Kolachev^{¹⁰⁷^,^∗}, H. Kolanoski¹⁶, V. Kolesnikov⁶⁴, I. Koletsou^89a, J. Koll⁸⁸, A.A. Komar⁹⁴, Y. Komori¹⁵⁵,
T.: Kondo⁶⁵, T. Kono^{⁴²^,^r}, A.I. Kononov⁴⁸, R. Konoplich^{¹⁰⁸^,^s}, N. Konstantinidis⁷⁷, R. Kopeliansky¹⁵², S. Koperny³⁸,
K.: Korcyl³⁹, K. Kordas¹⁵⁴, A. Korn¹¹⁸, A. Korol¹⁰⁷, I. Korolkov¹², E.V. Korolkova¹³⁹, V.A. Korotkov¹²⁸,
O.: Kortner⁹⁹, S. Kortner⁹⁹, V.V. Kostyukhin²¹, S. Kotov⁹⁹, V.M. Kotov⁶⁴, A. Kotwal⁴⁵, C. Kourkoumelis⁹,
V.: Kouskoura¹⁵⁴, A. Koutsman^159a, R. Kowalewski¹⁶⁹, T.Z. Kowalski³⁸, W. Kozanecki¹³⁶, A.S. Kozhin¹²⁸, V. Kral¹²⁷,

V.A.: Kramarenko⁹⁷, G. Kramberger⁷⁴, M.W. Krasny⁷⁸, A. Krasznahorkay¹⁰⁸, J.K. Kraus²¹, S. Kreiss¹⁰⁸, F. Krejci¹²⁷,
J.: Kretzschmar⁷³, N. Krieger⁵⁴, P. Krieger¹⁵⁸, K. Kroeninger⁵⁴, H. Kroha⁹⁹, J. Kroll¹²⁰, J. Kroseberg²¹, J. Krstic^13a,
U.: Kruchonak⁶⁴, H. Kr¨uger²¹, T. Kruker¹⁷, N. Krumnack⁶³, Z.V. Krumshteyn⁶⁴, A. Kruse¹⁷³, T. Kubota⁸⁶,
S.: Kuday^4a, S. Kuehn⁴⁸, A. Kugel^58c, T. Kuhl⁴², D. Kuhn⁶¹, V. Kukhtin⁶⁴, Y. Kulchitsky⁹⁰, S. Kuleshov^32b,
C.: Kummer⁹⁸, M. Kuna⁷⁸, J. Kunkle¹²⁰, A. Kupco¹²⁵, H. Kurashige⁶⁶, M. Kurata¹⁶⁰, Y.A. Kurochkin⁹⁰, V. Kus¹²⁵,

E.S.: Kuwertz¹⁴⁷, M. Kuze¹⁵⁷, J. Kvita¹⁴², R. Kwee¹⁶, A. La Rosa⁴⁹, L. La Rotonda^{^37a^,^37b}, L. Labarga⁸⁰, J. Labbe⁵,
S.: Lablak^135a, C. Lacasta¹⁶⁷, F. Lacava^{^132a^,^132b}, J. Lacey²⁹, H. Lacker¹⁶, D. Lacour⁷⁸, V.R. Lacuesta¹⁶⁷, E. Ladygin⁶⁴,
R.: Lafaye⁵, B. Laforge⁷⁸, T. Lagouri¹⁷⁶, S. Lai⁴⁸, E. Laisne⁵⁵, M. Lamanna³⁰, L. Lambourne⁷⁷, C.L. Lampen⁷,
W.: Lampl⁷, E. Lancon¹³⁶, U. Landgraf⁴⁸, M.P.J. Landon⁷⁵, V.S. Lang^58a, C. Lange⁴², A.J. Lankford¹⁶³, F. Lanni²⁵,
K.: Lantzsch¹⁷⁵, S. Laplace⁷⁸, C. Lapoire²¹, J.F. Laporte¹³⁶, T. Lari^89a, A. Larner¹¹⁸, M. Lassnig³⁰, P. Laurelli⁴⁷,
V.: Lavorini^{^37a^,^37b}, W. Lavrijsen¹⁵, P. Laycock⁷³, T. Lazovich⁵⁷, O. Le Dortz⁷⁸, E. Le Guirriec⁸³, E. Le Menedeu¹²,
T.: LeCompte⁶, F. Ledroit-Guillon⁵⁵, H. Lee¹⁰⁵, J.S.H. Lee¹¹⁶, S.C. Lee¹⁵¹, L. Lee¹⁷⁶, M. Lefebvre¹⁶⁹,
M.: Legendre¹³⁶, F. Legger⁹⁸, C. Leggett¹⁵, M. Lehmacher²¹, G. Lehmann Miotto³⁰, X. Lei⁷, M.A.L. Leite^24d,
R.: Leitner¹²⁶, D. Lellouch¹⁷², B. Lemmer⁵⁴, V. Lendermann^58a, K.J.C. Leney^145b, T. Lenz¹⁰⁵, G. Lenzen¹⁷⁵,
B.: Lenzi³⁰, K. Leonhardt⁴⁴, S. Leontsinis¹⁰, F. Lepold^58a, C. Leroy⁹³, J-R. Lessard¹⁶⁹, C.G. Lester²⁸, C.M. Lester¹²⁰,
J.: Levˆeque⁵, D. Levin⁸⁷, L.J. Levinson¹⁷², A. Lewis¹¹⁸, G.H. Lewis¹⁰⁸, A.M. Leyko²¹, M. Leyton¹⁶, B. Li⁸³, H. Li¹⁴⁸,

H.L.: Li³¹, S. Li^{^33b^,^t}, X. Li⁸⁷, Z. Liang^{¹¹⁸^,^u}, H. Liao³⁴, B. Liberti^133a, P. Lichard³⁰, M. Lichtnecker⁹⁸, K. Lie¹⁶⁵,
W.: Liebig¹⁴, C. Limbach²¹, A. Limosani⁸⁶, M. Limper⁶², S.C. Lin^{¹⁵¹^,^v}, F. Linde¹⁰⁵, J.T. Linnemann⁸⁸, E. Lipeles¹²⁰,
A.: Lipniacka¹⁴, T.M. Liss¹⁶⁵, D. Lissauer²⁵, A. Lister⁴⁹, A.M. Litke¹³⁷, C. Liu²⁹, D. Liu¹⁵¹, H. Liu⁸⁷, J.B. Liu⁸⁷,
K.: Liu^{^33b^,^w}, L. Liu⁸⁷, M. Liu^33b, Y. Liu^33b, M. Livan^{^119a^,^119b}, S.S.A. Livermore¹¹⁸, A. Lleres⁵⁵, J. Llorente Merino⁸⁰,

S.L. Lloyd⁷⁵, E. Lobodzinska⁴², P. Loch⁷, W.S. Lockman¹³⁷, T. Loddenkoetter²¹, F.K. Loebinger⁸², A. Loginov¹⁷⁶,

C.W.: Loh¹⁶⁸, T. Lohse¹⁶, K. Lohwasser⁴⁸, M. Lokajicek¹²⁵, V.P. Lombardo⁵, J.D. Long⁸⁷, R.E. Long⁷¹, L. Lopes^124a,
D.: Lopez Mateos⁵⁷, J. Lorenz⁹⁸, N. Lorenzo Martinez¹¹⁵, M. Losada¹⁶², P. Loscutoﬀ¹⁵, F. Lo Sterzo^{^132a^,^132b},

M.J. Losty^{^159a^,^∗}, X. Lou⁴¹, A. Lounis¹¹⁵, K.F. Loureiro¹⁶², J. Love⁶, P.A. Love⁷¹, A.J. Lowe^{¹⁴³^,^e}, F. Lu^33a,

H.J.: Lubatti¹³⁸, C. Luci^{^132a^,^132b}, A. Lucotte⁵⁵, A. Ludwig⁴⁴, D. Ludwig⁴², I. Ludwig⁴⁸, J. Ludwig⁴⁸, F. Luehring⁶⁰,
G.: Luijckx¹⁰⁵, W. Lukas⁶¹, L. Luminari^132a, E. Lund¹¹⁷, B. Lund-Jensen¹⁴⁷, B. Lundberg⁷⁹, J. Lundberg^{^146a^,^146b},
O.: Lundberg^{^146a^,^146b}, J. Lundquist³⁶, M. Lungwitz⁸¹, D. Lynn²⁵, E. Lytken⁷⁹, H. Ma²⁵, L.L. Ma¹⁷³, G. Maccarrone⁴⁷,
A.: Macchiolo⁹⁹, B. Maˇ,

cek⁷⁴, J. Machado Miguens^124a, R. Mackeprang³⁶, R.J. Madaras¹⁵, H.J. Maddocks⁷¹

W.F.: Mader⁴⁴, R. Maenner^58c, T. Maeno²⁵, P. M¨attig¹⁷⁵, S. M¨attig⁸¹, L. Magnoni¹⁶³, E. Magradze⁵⁴, K. Mahboubi⁴⁸,
J.: Mahlstedt¹⁰⁵, S. Mahmoud⁷³, G. Mahout¹⁸, C. Maiani¹³⁶, C. Maidantchik^24a, A. Maio^{^124a^,^b}, S. Majewski²⁵,
Y.: Makida⁶⁵, N. Makovec¹¹⁵, P. Mal¹³⁶, B. Malaescu³⁰, Pa. Malecki³⁹, P. Malecki³⁹, V.P. Maleev¹²¹, F. Malek⁵⁵,
U.: Mallik⁶², D. Malon⁶, C. Malone¹⁴³, S. Maltezos¹⁰, V. Malyshev¹⁰⁷, S. Malyukov³⁰, R. Mameghani⁹⁸,
J.: Mamuzic^13b, A. Manabe⁶⁵, L. Mandelli^89a, I. Mandic´⁷⁴, R. Mandrysch¹⁶, J. Maneira^124a, A. Manfredini⁹⁹,

P.S.: Mangeard⁸⁸, L. Manhaes de Andrade Filho^24b, J.A. Manjarres Ramos¹³⁶, A. Mann⁵⁴, P.M. Manning¹³⁷,
A.: Manousakis-Katsikakis⁹, B. Mansoulie¹³⁶, A. Mapelli³⁰, L. Mapelli³⁰, L. March¹⁶⁷, J.F. Marchand²⁹,
F.: Marchese^{^133a^,^133b}, G. Marchiori⁷⁸, M. Marcisovsky¹²⁵, C.P. Marino¹⁶⁹, F. Marroquim^24a, Z. Marshall³⁰,

F.K. Martens¹⁵⁸, L.F. Marti¹⁷, S. Marti-Garcia¹⁶⁷, B. Martin³⁰, B. Martin⁸⁸, J.P. Martin⁹³, T.A. Martin¹⁸,

V.J. Martin⁴⁶, B. Martin dit Latour⁴⁹, S. Martin-Haugh¹⁴⁹, M. Martinez¹², V. Martinez Outschoorn⁵⁷,

A.C.: Martyniuk¹⁶⁹, M. Marx⁸², F. Marzano^132a, A. Marzin¹¹¹, L. Masetti⁸¹, T. Mashimo¹⁵⁵, R. Mashinistov⁹⁴,
J.: Masik⁸², A.L. Maslennikov¹⁰⁷, I. Massa^{^20a^,^20b}, G. Massaro¹⁰⁵, N. Massol⁵, P. Mastrandrea¹⁴⁸,
A.: Mastroberardino^{^37a^,^37b}, T. Masubuchi¹⁵⁵, P. Matricon¹¹⁵, H. Matsunaga¹⁵⁵, T. Matsushita⁶⁶, C. Mattravers^{¹¹⁸^,^c},
J.: Maurer⁸³, S.J. Maxﬁeld⁷³, A. Mayne¹³⁹, R. Mazini¹⁵¹, M. Mazur²¹, L. Mazzaferro^{^133a^,^133b}, M. Mazzanti^89a,
J.: Mc Donald⁸⁵, S.P. Mc Kee⁸⁷, A. McCarn¹⁶⁵, R.L. McCarthy¹⁴⁸, T.G. McCarthy²⁹, N.A. McCubbin¹²⁹,

K.W.: McFarlane^{⁵⁶^,^∗}, J.A. Mcfayden¹³⁹, G. Mchedlidze^51b, T. Mclaughlan¹⁸, S.J. McMahon¹²⁹, R.A. McPherson^{¹⁶⁹^,^k},
A.: Meade⁸⁴, J. Mechnich¹⁰⁵, M. Mechtel¹⁷⁵, M. Medinnis⁴², R. Meera-Lebbai¹¹¹, T. Meguro¹¹⁶, R. Mehdiyev⁹³,
S.: Mehlhase³⁶, A. Mehta⁷³, K. Meier^58a, B. Meirose⁷⁹, C. Melachrinos³¹, B.R. Mellado Garcia¹⁷³, F. Meloni^{^89a^,^89b},
L.: Mendoza Navas¹⁶², Z. Meng^{¹⁵¹^,^x}, A. Mengarelli^{^20a^,^20b}, S. Menke⁹⁹, E. Meoni¹⁶¹, K.M. Mercurio⁵⁷, P. Mermod⁴⁹,
L.: Merola^{^102a^,^102b}, C. Meroni^89a, F.S. Merritt³¹, H. Merritt¹⁰⁹, A. Messina^{³⁰^,^y}, J. Metcalfe²⁵, A.S. Mete¹⁶³,
C.: Meyer⁸¹, C. Meyer³¹, J-P. Meyer¹³⁶, J. Meyer¹⁷⁴, J. Meyer⁵⁴, T.C. Meyer³⁰, S. Michal³⁰, L. Micu^26a,

R.P. Middleton¹²⁹, S. Migas⁷³, L. Mijovi´c¹³⁶, G. Mikenberg¹⁷², M. Mikestikova¹²⁵, M. Mikuˇz⁷⁴, D.W. Miller³¹,

R.J. Miller⁸⁸, W.J. Mills¹⁶⁸, C. Mills⁵⁷, A. Milov¹⁷², D.A. Milstead^{^146a^,^146b}, D. Milstein¹⁷², A.A. Minaenko¹²⁸,

M.Mi˜,

nano Moya¹⁶⁷, I.A. Minashvili⁶⁴, A.I. Mincer¹⁰⁸, B. Mindur³⁸, M. Mineev⁶⁴, Y. Ming¹⁷³, L.M. Mir¹²

G. Mirabelli^132a, J. Mitrevski¹³⁷, V.A. Mitsou¹⁶⁷, S. Mitsui⁶⁵, P.S. Miyagawa¹³⁹, J.U. Mj¨ornmark⁷⁹, T. Moa^{^146a^,^146b},

V. Moeller²⁸, K. M¨oser²¹, S. Mohapatra¹⁴⁸, W. Mohr⁴⁸, R. Moles-Valls¹⁶⁷, A. Molfetas³⁰, J. Monk⁷⁷

onig⁴², N. M¨,

E. Monnier⁸³, J. Montejo Berlingen¹², F. Monticelli⁷⁰, S. Monzani^{^20a^,^20b}, R.W. Moore³, G.F. Moorhead⁸⁶,

C. Mora Herrera⁴⁹, A. Moraes⁵³, N. Morange¹³⁶, J. Morel⁵⁴, G. Morello^{^37a^,^37b}, D. Moreno⁸¹, M. Moreno Ll´acer,

P. Morettini^50a, M. Morgenstern⁴⁴, M. Morii⁵⁷, A.K. Morley³⁰, G. Mornacchi³⁰, J.D. Morris⁷⁵, L. Morvaj¹⁰¹,

H.G.: Moser⁹⁹, M. Mosidze^51b, J. Moss¹⁰⁹, R. Mount¹⁴³, E. Mountricha^{¹⁰^,^z}, S.V. Mouraviev^{⁹⁴^,^∗}, E.J.W. Moyse⁸⁴,
F.: Mueller^58a, J. Mueller¹²³, K. Mueller²¹, T.A. M¨uller⁹⁸, T. Mueller⁸¹, D. Muenstermann³⁰, Y. Munwes¹⁵³,

W.J.: Murray¹²⁹, I. Mussche¹⁰⁵, E. Musto^{^102a^,^102b}, A.G. Myagkov¹²⁸, M. Myska¹²⁵, O. Nackenhorst⁵⁴, J. Nadal¹²,
K.: Nagai¹⁶⁰, R. Nagai¹⁵⁷, K. Nagano⁶⁵, A. Nagarkar¹⁰⁹, Y. Nagasaka⁵⁹, M. Nagel⁹⁹, A.M. Nairz³⁰, Y. Nakahama³⁰,
K.: Nakamura¹⁵⁵, T. Nakamura¹⁵⁵, I. Nakano¹¹⁰, G. Nanava²¹, A. Napier¹⁶¹, R. Narayan^58b, M. Nash^{⁷⁷^,^c},
T.: Nattermann²¹, T. Naumann⁴², G. Navarro¹⁶², H.A. Neal⁸⁷, P.Yu. Nechaeva⁹⁴, T.J. Neep⁸², A. Negri^{^119a^,^119b},
G.: Negri³⁰, M. Negrini^20a, S. Nektarijevic⁴⁹, A. Nelson¹⁶³, T.K. Nelson¹⁴³, S. Nemecek¹²⁵, P. Nemethy¹⁰⁸,

A.A. Nepomuceno^24a, M. Nessi^{³⁰^,^aa}, M.S. Neubauer¹⁶⁵, M. Neumann¹⁷⁵, A. Neusiedl⁸¹, R.M. Neves¹⁰⁸, P. Nevski²⁵,

F.M.: Newcomer¹²⁰, P.R. Newman¹⁸, V. Nguyen Thi Hong¹³⁶, R.B. Nickerson¹¹⁸, R. Nicolaidou¹³⁶, B. Nicquevert³⁰,
F.: Niedercorn¹¹⁵, J. Nielsen¹³⁷, N. Nikiforou³⁵, A. Nikiforov¹⁶, V. Nikolaenko¹²⁸, I. Nikolic-Audit⁷⁸, K. Nikolics⁴⁹,
K.: Nikolopoulos¹⁸, H. Nilsen⁴⁸, P. Nilsson⁸, Y. Ninomiya¹⁵⁵, A. Nisati^132a, R. Nisius⁹⁹, T. Nobe¹⁵⁷, L. Nodulman⁶,
M.: Nomachi¹¹⁶, I. Nomidis¹⁵⁴, S. Norberg¹¹¹, M. Nordberg³⁰, P.R. Norton¹²⁹, J. Novakova¹²⁶, M. Nozaki⁶⁵,
L.: Nozka¹¹³, I.M. Nugent^159a, A.-E. Nuncio-Quiroz²¹, G. Nunes Hanninger⁸⁶, T. Nunnemann⁹⁸, E. Nurse⁷⁷,

B.J.: O’Brien⁴⁶, D.C. O’Neil¹⁴², V. O’Shea⁵³, L.B. Oakes⁹⁸, F.G. Oakham^{²⁹^,^d}, H. Oberlack⁹⁹, J. Ocariz⁷⁸, A. Ochi⁶⁶,
S.: Oda⁶⁹, S. Odaka⁶⁵, J. Odier⁸³, H. Ogren⁶⁰, A. Oh⁸², S.H. Oh⁴⁵, C.C. Ohm³⁰, T. Ohshima¹⁰¹, W. Okamura¹¹⁶,
H.: Okawa²⁵, Y. Okumura³¹, T. Okuyama¹⁵⁵, A. Olariu^26a, A.G. Olchevski⁶⁴, S.A. Olivares Pino^32a, M. Oliveira^{^124a^,^h},
D.: Oliveira Damazio²⁵, E. Oliver Garcia¹⁶⁷, D. Olivito¹²⁰, A. Olszewski³⁹, J. Olszowska³⁹, A. Onofre^{^124a^,^ab},

P.U.E.: Onyisi³¹, C.J. Oram^159a, M.J. Oreglia³¹, Y. Oren¹⁵³, D. Orestano^{^134a^,^134b}, N. Orlando^{^72a^,^72b}, I. Orlov¹⁰⁷,
C.: Oropeza Barrera⁵³, R.S. Orr¹⁵⁸, B. Osculati^{^50a^,^50b}, R. Ospanov¹²⁰, C. Osuna¹², G. Otero y Garzon²⁷,

J.P.: Ottersbach¹⁰⁵, M. Ouchrif^135d, E.A. Ouellette¹⁶⁹, F. Ould-Saada¹¹⁷, A. Ouraou¹³⁶, Q. Ouyang^33a,
A.: Ovcharova¹⁵, M. Owen⁸², S. Owen¹³⁹, V.E. Ozcan^19a, N. Ozturk⁸, A. Pacheco Pages¹², C. Padilla Aranda¹²,
S.: Pagan Griso¹⁵, E. Paganis¹³⁹, C. Pahl⁹⁹, F. Paige²⁵, P. Pais⁸⁴, K. Pajchel¹¹⁷, G. Palacino^159b, C.P. Paleari⁷,
S.: Palestini³⁰, D. Pallin³⁴, A. Palma^124a, J.D. Palmer¹⁸, Y.B. Pan¹⁷³, E. Panagiotopoulou¹⁰, J.G. Panduro Vazquez⁷⁶,
P.: Pani¹⁰⁵, N. Panikashvili⁸⁷, S. Panitkin²⁵, D. Pantea^26a, A. Papadelis^146a, Th.D. Papadopoulou¹⁰, A. Paramonov⁶,
D.: Paredes Hernandez³⁴, W. Park^{²⁵^,^ac}, M.A. Parker²⁸, F. Parodi^{^50a^,^50b}, J.A. Parsons³⁵, U. Parzefall⁴⁸, S. Pashapour⁵⁴,
E.: Pasqualucci^132a, S. Passaggio^50a, A. Passeri^134a, F. Pastore^{^134a^,^134b^,^∗}, Fr. Pastore⁷⁶, G. P´asztor^{⁴⁹^,^ad}, S. Pataraia¹⁷⁵,
N.: Patel¹⁵⁰, J.R. Pater⁸², S. Patricelli^{^102a^,^102b}, T. Pauly³⁰, M. Pecsy^144a, S. Pedraza Lopez¹⁶⁷, M.I. Pedraza Morales¹⁷³,

S.V.: Peleganchuk¹⁰⁷, D. Pelikan¹⁶⁶, H. Peng^33b, B. Penning³¹, A. Penson³⁵, J. Penwell⁶⁰, M. Perantoni^24a,
K.: Perez^{³⁵^,^ae}, T. Perez Cavalcanti⁴², E. Perez Codina^159a, M.T. P´erez Garc´ıa-Esta˜n¹⁶⁷, V. Perez Reale³⁵,
L.: Perini^{^89a^,^89b}, H. Pernegger³⁰, R. Perrino^72a, P. Perrodo⁵, V.D. Peshekhonov⁶⁴, K. Peters³⁰, B.A. Petersen³⁰,
J.: Petersen³⁰, T.C. Petersen³⁶, E. Petit⁵, A. Petridis¹⁵⁴, C. Petridou¹⁵⁴, E. Petrolo^132a, F. Petrucci^{^134a^,^134b},
D.: Petschull⁴², M. Petteni¹⁴², R. Pezoa^32b, A. Phan⁸⁶, P.W. Phillips¹²⁹, G. Piacquadio³⁰, A. Picazio⁴⁹, E. Piccaro⁷⁵,
M.: Piccinini^{^20a^,^20b}, S.M. Piec⁴², R. Piegaia²⁷, D.T. Pignotti¹⁰⁹, J.E. Pilcher³¹, A.D. Pilkington⁸², J. Pina^{^124a^,^b},
M.: Pinamonti^{^164a^,^164c}, A. Pinder¹¹⁸, J.L. Pinfold³, B. Pinto^124a, C. Pizio^{^89a^,^89b}, M. Plamondon¹⁶⁹, M.-A. Pleier²⁵,
E.: Plotnikova⁶⁴, A. Poblaguev²⁵, S. Poddar^58a, F. Podlyski³⁴, L. Poggioli¹¹⁵, D. Pohl²¹, M. Pohl⁴⁹, G. Polesello^119a,

A. Policicchio^{^37a^,^37b}, R. Polifka¹⁵⁸, A. Polini^20a, J. Poll⁷⁵, V. Polychronakos²⁵, D. Pomeroy²³, K. Pomm`,

L. Pontecorvo^132a, B.G. Pope⁸⁸, G.A. Popeneciu^26a, D.S. Popovic^13a, A. Poppleton³⁰, X. Portell Bueso³⁰,

G.E.: Pospelov⁹⁹, S. Pospisil¹²⁷, I.N. Potrap⁹⁹, C.J. Potter¹⁴⁹, C.T. Potter¹¹⁴, G. Poulard³⁰, J. Poveda⁶⁰,
V.: Pozdnyakov⁶⁴, R. Prabhu⁷⁷, P. Pralavorio⁸³, A. Pranko¹⁵, S. Prasad³⁰, R. Pravahan²⁵, S. Prell⁶³, K. Pretzl¹⁷,
D.: Price⁶⁰, J. Price⁷³, L.E. Price⁶, D. Prieur¹²³, M. Primavera^72a, K. Prokoﬁev¹⁰⁸, F. Prokoshin^32b, S. Protopopescu²⁵,
J.: Proudfoot⁶, X. Prudent⁴⁴, M. Przybycien³⁸, H. Przysiezniak⁵, S. Psoroulas²¹, E. Ptacek¹¹⁴, E. Pueschel⁸⁴,
J.: Purdham⁸⁷, M. Purohit^{²⁵^,^ac}, P. Puzo¹¹⁵, Y. Pylypchenko⁶², J. Qian⁸⁷, A. Quadt⁵⁴, D.R. Quarrie¹⁵, W.B. Quayle¹⁷³,
F.: Quinonez^32a, M. Raas¹⁰⁴, S. Raddum¹¹⁷, V. Radeka²⁵, V. Radescu⁴², P. Radloﬀ¹¹⁴, T. Rador^19a, F. Ragusa^{^89a^,^89b},
G.: Rahal¹⁷⁸, A.M. Rahimi¹⁰⁹, D. Rahm²⁵, S. Rajagopalan²⁵, M. Rammensee⁴⁸, M. Rammes¹⁴¹,

A.S. Randle-Conde⁴⁰, K. Randrianarivony²⁹, F. Rauscher⁹⁸, T.C. Rave⁴⁸, M. Raymond³⁰, A.L. Read¹¹⁷,

D.M.: Rebuzzi^{^119a^,^119b}, A. Redelbach¹⁷⁴, G. Redlinger²⁵, R. Reece¹²⁰, K. Reeves⁴¹, E. Reinherz-Aronis¹⁵³,
A.: Reinsch¹¹⁴, I. Reisinger⁴³, C. Rembser³⁰, Z.L. Ren¹⁵¹, A. Renaud¹¹⁵, M. Rescigno^132a, S. Resconi^89a,
B.: Resende¹³⁶, P. Reznicek⁹⁸, R. Rezvani¹⁵⁸, R. Richter⁹⁹, E. Richter-Was^{⁵^,^af}, M. Ridel⁷⁸, M. Rijpstra¹⁰⁵,
M.: Rijssenbeek¹⁴⁸, A. Rimoldi^{^119a^,^119b}, L. Rinaldi^20a, R.R. Rios⁴⁰, I. Riu¹², G. Rivoltella^{^89a^,^89b}, F. Rizatdinova¹¹²,
E.: Rizvi⁷⁵, S.H. Robertson^{⁸⁵^,^k}, A. Robichaud-Veronneau¹¹⁸, D. Robinson²⁸, J.E.M. Robinson⁸², A. Robson⁵³,

J.G.: Rocha de Lima¹⁰⁶, C. Roda^{^122a^,^122b}, D. Roda Dos Santos³⁰, A. Roe⁵⁴, S. Roe³⁰, O. Røhne¹¹⁷, S. Rolli¹⁶¹,
A.: Romaniouk⁹⁶, M. Romano^{^20a^,^20b}, G. Romeo²⁷, E. Romero Adam¹⁶⁷, N. Rompotis¹³⁸, L. Roos⁷⁸, E. Ros¹⁶⁷,
S.: Rosati^132a, K. Rosbach⁴⁹, A. Rose¹⁴⁹, M. Rose⁷⁶, G.A. Rosenbaum¹⁵⁸, E.I. Rosenberg⁶³, P.L. Rosendahl¹⁴,
O.: Rosenthal¹⁴¹, L. Rosselet⁴⁹, V. Rossetti¹², E. Rossi^{^132a^,^132b}, L.P. Rossi^50a, M. Rotaru^26a, I. Roth¹⁷², J. Rothberg¹³⁸,
D.: Rousseau¹¹⁵, C.R. Royon¹³⁶, A. Rozanov⁸³, Y. Rozen¹⁵², X. Ruan^{^33a^,^ag}, F. Rubbo¹², I. Rubinskiy⁴²,
N.: Ruckstuhl¹⁰⁵, V.I. Rud⁹⁷, C. Rudolph⁴⁴, G. Rudolph⁶¹, F. R¨uhr⁷, A. Ruiz-Martinez⁶³, L. Rumyantsev⁶⁴,
Z.: Rurikova⁴⁸, N.A. Rusakovich⁶⁴, J.P. Rutherfoord⁷, P. Ruzicka¹²⁵, Y.F. Ryabov¹²¹, M. Rybar¹²⁶, G. Rybkin¹¹⁵,

N.C.: Ryder¹¹⁸, A.F. Saavedra¹⁵⁰, I. Sadeh¹⁵³, H.F-W. Sadrozinski¹³⁷, R. Sadykov⁶⁴, F. Safai Tehrani^132a,
H.: Sakamoto¹⁵⁵, G. Salamanna⁷⁵, A. Salamon^133a, M. Saleem¹¹¹, D. Salek³⁰, D. Salihagic⁹⁹, A. Salnikov¹⁴³,
J.: Salt¹⁶⁷, B.M. Salvachua Ferrando⁶, D. Salvatore^{^37a^,^37b}, F. Salvatore¹⁴⁹, A. Salvucci¹⁰⁴, A. Salzburger³⁰,
D.: Sampsonidis¹⁵⁴, B.H. Samset¹¹⁷, A. Sanchez^{^102a^,^102b}, V. Sanchez Martinez¹⁶⁷, H. Sandaker¹⁴, H.G. Sander⁸¹,

M.P.: Sanders⁹⁸, M. Sandhoﬀ¹⁷⁵, T. Sandoval²⁸, C. Sandoval¹⁶², R. Sandstroem⁹⁹, D.P.C. Sankey¹²⁹, A. Sansoni⁴⁷,
C.: Santamarina Rios⁸⁵, C. Santoni³⁴, R. Santonico^{^133a^,^133b}, H. Santos^124a, J.G. Saraiva^124a, T. Sarangi¹⁷³,
E.: Sarkisyan-Grinbaum⁸, F. Sarri^{^122a^,^122b}, G. Sartisohn¹⁷⁵, O. Sasaki⁶⁵, Y. Sasaki¹⁵⁵, N. Sasao⁶⁷, I. Satsounkevitch⁹⁰,
G.: Sauvage^{⁵^,^∗}, E. Sauvan⁵, J.B. Sauvan¹¹⁵, P. Savard^{¹⁵⁸^,^d}, V. Savinov¹²³, D.O. Savu³⁰, L. Sawyer^{²⁵^,^m}, D.H. Saxon⁵³,
J.: Saxon¹²⁰, C. Sbarra^20a, A. Sbrizzi^{^20a^,^20b}, D.A. Scannicchio¹⁶³, M. Scarcella¹⁵⁰, J. Schaarschmidt¹¹⁵, P. Schacht⁹⁹,
D.: Schaefer¹²⁰, U. Schafer¨⁸¹, A. Schaelicke⁴⁶, S. Schaepe²¹, S. Schaetzel^58b, A.C. Schaﬀer¹¹⁵, D. Schaile⁹⁸,

R.D. Schamberger¹⁴⁸, A.G. Schamov¹⁰⁷, V. Scharf^58a, V.A. Schegelsky¹²¹, D. Scheirich⁸⁷, M. Schernau¹⁶³,

M.I.: Scherzer³⁵, C. Schiavi^{^50a^,^50b}, J. Schieck⁹⁸, M. Schioppa^{^37a^,^37b}, S. Schlenker³⁰, P. Schmid³⁰, E. Schmidt⁴⁸,
K.: Schmieden²¹, C. Schmitt⁸¹, S. Schmitt^58b, M. Schmitz²¹, B. Schneider¹⁷, U. Schnoor⁴⁴, L. Schoeﬀel¹³⁶,
A.: Schoening^58b, A.L.S. Schorlemmer⁵⁴, M. Schott³⁰, D. Schouten^159a, J. Schovancova¹²⁵, M. Schram⁸⁵,
C.: Schroeder⁸¹, N. Schroer^58c, M.J. Schultens²¹, J. Schultes¹⁷⁵, H.-C. Schultz-Coulon^58a, H. Schulz¹⁶,
M.: Schumacher⁴⁸, B.A. Schumm¹³⁷, Ph. Schune¹³⁶, C. Schwanenberger⁸², A. Schwartzman¹⁴³, Ph. Schwegler⁹⁹, Ph. Schwemling⁷⁸, R. Schwienhorst⁸⁸, R. Schwierz⁴⁴, J. Schwindling¹³⁶, T. Schwindt²¹, M. Schwoerer⁵,
G.: Sciolla²³, W.G. Scott¹²⁹, J. Searcy¹¹⁴, G. Sedov⁴², E. Sedykh¹²¹, S.C. Seidel¹⁰³, A. Seiden¹³⁷, F. Seifert⁴⁴,

J.M.: Seixas^24a, G. Sekhniaidze^102a, S.J. Sekula⁴⁰, K.E. Selbach⁴⁶, D.M. Seliverstov¹²¹, B. Sellden^146a, G. Sellers⁷³,
M.: Seman^144b, N. Semprini-Cesari^{^20a^,^20b}, C. Serfon⁹⁸, L. Serin¹¹⁵, L. Serkin⁵⁴, R. Seuster^159a, H. Severini¹¹¹,
A.: Sfyrla³⁰, E. Shabalina⁵⁴, M. Shamim¹¹⁴, L.Y. Shan^33a, J.T. Shank²², Q.T. Shao⁸⁶, M. Shapiro¹⁵, P.B. Shatalov⁹⁵,
K.: Shaw^{^164a^,^164c}, D. Sherman¹⁷⁶, P. Sherwood⁷⁷, S. Shimizu¹⁰¹, M. Shimojima¹⁰⁰, T. Shin⁵⁶, M. Shiyakova⁶⁴,
A.: Shmeleva⁹⁴, M.J. Shochet³¹, D. Short¹¹⁸, S. Shrestha⁶³, E. Shulga⁹⁶, M.A. Shupe⁷, P. Sicho¹²⁵, A. Sidoti^132a,
F.: Siegert⁴⁸, Dj. Sijacki^13a, O. Silbert¹⁷², J. Silva^124a, Y. Silver¹⁵³, D. Silverstein¹⁴³, S.B. Silverstein^146a, V. Simak¹²⁷,
O.: Simard¹³⁶, Lj. Simic^13a, S. Simion¹¹⁵, E. Simioni⁸¹, B. Simmons⁷⁷, R. Simoniello^{^89a^,^89b}, M. Simonyan³⁶,
P.: Sinervo¹⁵⁸, N.B. Sinev¹¹⁴, V. Sipica¹⁴¹, G. Siragusa¹⁷⁴, A. Sircar²⁵, A.N. Sisakyan^{⁶⁴^,^∗}, S.Yu. Sivoklokov⁹⁷,
J.: Sj¨olin^{^146a^,^146b}, T.B. Sjursen¹⁴, L.A. Skinnari¹⁵, H.P. Skottowe⁵⁷, K. Skovpen¹⁰⁷, P. Skubic¹¹¹, M. Slater¹⁸,
T.: Slavicek¹²⁷, K. Sliwa¹⁶¹, V. Smakhtin¹⁷², B.H. Smart⁴⁶, L. Smestad¹¹⁷, S.Yu. Smirnov⁹⁶, Y. Smirnov⁹⁶,

L.N. Smirnova⁹⁷, O. Smirnova⁷⁹, B.C. Smith⁵⁷, D. Smith¹⁴³, K.M. Smith⁵³, M. Smizanska⁷¹, K. Smolek¹²⁷,

A.A.: Snesarev⁹⁴, S.W. Snow⁸², J. Snow¹¹¹, S. Snyder²⁵, R. Sobie^{¹⁶⁹^,^k}, J. Sodomka¹²⁷, A. Soﬀer¹⁵³, C.A. Solans¹⁶⁷,
M.: Solar¹²⁷, J. Solc¹²⁷, E.Yu. Soldatov⁹⁶, U. Soldevila¹⁶⁷, E. Solfaroli Camillocci^{^132a^,^132b}, A.A. Solodkov¹²⁸,

O.V.: Solovyanov¹²⁸, V. Solovyev¹²¹, N. Soni¹, V. Sopko¹²⁷, B. Sopko¹²⁷, M. Sosebee⁸, R. Soualah^{^164a^,^164c},
A.: Soukharev¹⁰⁷, S. Spagnolo^{^72a^,^72b}, F. Span`o⁷⁶, W.R. Spearman⁵⁷, R. Spighi^20a, G. Spigo³⁰, R. Spiwoks³⁰,
M.: Spousta^{¹²⁶^,^ah}, T. Spreitzer¹⁵⁸, B. Spurlock⁸, R.D. St. Denis⁵³, J. Stahlman¹²⁰, R. Stamen^58a, E. Stanecka³⁹,

R.W.: Stanek⁶, C. Stanescu^134a, M. Stanescu-Bellu⁴², M.M. Stanitzki⁴², S. Stapnes¹¹⁷, E.A. Starchenko¹²⁸, J. Stark⁵⁵,
P.: Staroba¹²⁵, P. Starovoitov⁴², R. Staszewski³⁹, A. Staude⁹⁸, P. Stavina^{^144a^,^∗}, G. Steele⁵³, P. Steinbach⁴⁴,
P.: Steinberg²⁵, I. Stekl¹²⁷, B. Stelzer¹⁴², H.J. Stelzer⁸⁸, O. Stelzer-Chilton^159a, H. Stenzel⁵², S. Stern⁹⁹,

G.A. Stewart³⁰, J.A. Stillings²¹, M.C. Stockton⁸⁵, K. Stoerig⁴⁸, G. Stoicea^26a, S. Stonjek⁹⁹, P. Strachota¹²⁶,

A.R.: Stradling⁸, A. Straessner⁴⁴, J. Strandberg¹⁴⁷, S. Strandberg^{^146a^,^146b}, A. Strandlie¹¹⁷, M. Strang¹⁰⁹, E. Strauss¹⁴³,
M.: Strauss¹¹¹, P. Strizenec^144b, R. Str¨ohmer¹⁷⁴, D.M. Strom¹¹⁴, J.A. Strong^{⁷⁶^,^∗}, R. Stroynowski⁴⁰, B. Stugu¹⁴,
I.: Stumer^{²⁵^,^∗}, J. Stupak¹⁴⁸, P. Sturm¹⁷⁵, N.A. Styles⁴², D.A. Soh^{¹⁵¹^,^u}, D. Su¹⁴³, HS. Subramania³, R. Subramaniam²⁵,
A.: Succurro¹², Y. Sugaya¹¹⁶, C. Suhr¹⁰⁶, M. Suk¹²⁶, V.V. Sulin⁹⁴, S. Sultansoy^4d, T. Sumida⁶⁷, X. Sun⁵⁵,

J.E.: Sundermann⁴⁸, K. Suruliz¹³⁹, G. Susinno^{^37a^,^37b}, M.R. Sutton¹⁴⁹, Y. Suzuki⁶⁵, Y. Suzuki⁶⁶, M. Svatos¹²⁵,
S.: Swedish¹⁶⁸, I. Sykora^144a, T. Sykora¹²⁶, J. S´,

anchez¹⁶⁷, D. Ta¹⁰⁵, K. Tackmann⁴², A. Taﬀard¹⁶³, R. Taﬁrout^159a

N. Taiblum¹⁵³, Y. Takahashi¹⁰¹, H. Takai²⁵, R. Takashima⁶⁸, H. Takeda⁶⁶, T. Takeshita¹⁴⁰, Y. Takubo⁶⁵, M. Talby⁸³,

A. Talyshev^{107, f}, M.C. Tamsett²⁵, K.G. Tan⁸⁶, J. Tanaka¹⁵⁵, R. Tanaka¹¹⁵, S. Tanaka¹³¹, S. Tanaka⁶⁵,

A.J. Tanasijczuk¹⁴², K. Tani⁶⁶, N. Tannoury⁸³, S. Tapprogge⁸¹, D. Tardif¹⁵⁸, S. Tarem¹⁵², F. Tarrade²⁹,

G.F. Tartarelli^89a, P. Tas¹²⁶, M. Tasevsky¹²⁵, E. Tassi^{^37a^,^37b}, M. Tatarkhanov¹⁵, Y. Tayalati^135d, C. Taylor⁷⁷,

F.E.: Taylor⁹², G.N. Taylor⁸⁶, W. Taylor^159b, M. Teinturier¹¹⁵, F.A. Teischinger³⁰, M. Teixeira Dias Castanheira⁷⁵,
P.: Teixeira-Dias⁷⁶, K.K. Temming⁴⁸, H. Ten Kate³⁰, P.K. Teng¹⁵¹, S. Terada⁶⁵, K. Terashi¹⁵⁵, J. Terron⁸⁰, M. Testa⁴⁷,

R.J. Teuscher^{¹⁵⁸^,^k}, J. Therhaag²¹, T. Theveneaux-Pelzer⁷⁸, S. Thoma⁴⁸, J.P. Thomas¹⁸, E.N. Thompson³⁵, P.D. Thompson¹⁸, P.D. Thompson¹⁵⁸, A.S. Thompson⁵³, L.A. Thomsen³⁶, E. Thomson¹²⁰, M. Thomson²⁸,

W.M.: Thong⁸⁶, R.P. Thun⁸⁷, F. Tian³⁵, M.J. Tibbetts¹⁵, T. Tic¹²⁵, V.O. Tikhomirov⁹⁴, Y.A. Tikhonov^{107, f},
S.: Timoshenko⁹⁶, E. Tiouchichine⁸³, P. Tipton¹⁷⁶, S. Tisserant⁸³, T. Todorov⁵, S. Todorova-Nova¹⁶¹, B. Toggerson¹⁶³,
J.: Tojo⁶⁹, S. Tok´ar^144a, K. Tokushuku⁶⁵, K. Tollefson⁸⁸, M. Tomoto¹⁰¹, L. Tompkins³¹, K. Toms¹⁰³, A. Tonoyan¹⁴,
C.: Topfel¹⁷, N.D. Topilin⁶⁴, I. Torchiani³⁰, E. Torrence¹¹⁴, H. Torres⁷⁸, E. Torr´,

o Pastor¹⁶⁷, J. Toth^{⁸³^,^ad}, F. Touchard⁸³

D.R. Tovey¹³⁹, T. Trefzger¹⁷⁴, L. Tremblet³⁰, A. Tricoli³⁰, I.M. Trigger^159a, G. Trilling¹⁵, S. Trincaz-Duvoid⁷⁸,

M.F.: Tripiana⁷⁰, N. Triplett²⁵, W. Trischuk¹⁵⁸, B. Trocm´e⁵⁵, C. Troncon^89a, M. Trottier-McDonald¹⁴²,
M.: Trzebinski³⁹, A. Trzupek³⁹, C. Tsarouchas³⁰, J.C-L. Tseng¹¹⁸, M. Tsiakiris¹⁰⁵, P.V. Tsiareshka⁹⁰, D. Tsionou^{⁵^,^ai},
G.: Tsipolitis¹⁰, S. Tsiskaridze¹², V. Tsiskaridze⁴⁸, E.G. Tskhadadze^51a, I.I. Tsukerman⁹⁵, V. Tsulaia¹⁵, J.-W. Tsung²¹,
S.: Tsuno⁶⁵, D. Tsybychev¹⁴⁸, A. Tua¹³⁹, A. Tudorache^26a, V. Tudorache^26a, J.M. Tuggle³¹, M. Turala³⁹,
D.: Turecek¹²⁷, I. Turk Cakir^4e, E. Turlay¹⁰⁵, R. Turra^{^89a^,^89b}, P.M. Tuts³⁵, A. Tykhonov⁷⁴, M. Tylmad^{^146a^,^146b},
M.: Tyndel¹²⁹, G. Tzanakos⁹, K. Uchida²¹, I. Ueda¹⁵⁵, R. Ueno²⁹, M. Ugland¹⁴, M. Uhlenbrock²¹, M. Uhrmacher⁵⁴,
F.: Ukegawa¹⁶⁰, G. Unal³⁰, A. Undrus²⁵, G. Unel¹⁶³, Y. Unno⁶⁵, D. Urbaniec³⁵, P. Urquijo²¹, G. Usai⁸,
M.: Uslenghi^{^119a^,^119b}, L. Vacavant⁸³, V. Vacek¹²⁷, B. Vachon⁸⁵, S. Vahsen¹⁵, J. Valenta¹²⁵, S. Valentinetti^{^20a^,^20b},
A.: Valero¹⁶⁷, S. Valkar¹²⁶, E. Valladolid Gallego¹⁶⁷, S. Vallecorsa¹⁵², J.A. Valls Ferrer¹⁶⁷, R. Van Berg¹²⁰,

P.C.: Van Der Deijl¹⁰⁵, R. van der Geer¹⁰⁵, H. van der Graaf¹⁰⁵, R. Van Der Leeuw¹⁰⁵, E. van der Poel¹⁰⁵,
D.: van der Ster³⁰, N. van Eldik³⁰, P. van Gemmeren⁶, I. van Vulpen¹⁰⁵, M. Vanadia⁹⁹, W. Vandelli³⁰, R. Vanguri¹²⁰,
A.: Vaniachine⁶, P. Vankov⁴², F. Vannucci⁷⁸, R. Vari^132a, T. Varol⁸⁴, D. Varouchas¹⁵, A. Vartapetian⁸, K.E. Varvell¹⁵⁰,

V.I.: Vassilakopoulos⁵⁶, F. Vazeille³⁴, T. Vazquez Schroeder⁵⁴, G. Vegni^{^89a^,^89b}, J.J. Veillet¹¹⁵, F. Veloso^124a,
R.: Veness³⁰, S. Veneziano^132a, A. Ventura^{^72a^,^72b}, D. Ventura⁸⁴, M. Venturi⁴⁸, N. Venturi¹⁵⁸, V. Vercesi^119a,
M.: Verducci¹³⁸, W. Verkerke¹⁰⁵, J.C. Vermeulen¹⁰⁵, A. Vest⁴⁴, M.C. Vetterli^{¹⁴²^,^d}, I. Vichou¹⁶⁵, T. Vickey^{^145b^,^aj},

O.E. Vickey Boeriu^145b, G.H.A. Viehhauser¹¹⁸, S. Viel¹⁶⁸, M. Villa^{^20a^,^20b}, M. Villaplana Perez¹⁶⁷, E. Vilucchi⁴⁷,

M.G.: Vincter²⁹, E. Vinek³⁰, V.B. Vinogradov⁶⁴, M. Virchaux^{¹³⁶^,^∗}, J. Virzi¹⁵, O. Vitells¹⁷², M. Viti⁴², I. Vivarelli⁴⁸,
F.: Vives Vaque³, S. Vlachos¹⁰, D. Vladoiu⁹⁸, M. Vlasak¹²⁷, A. Vogel²¹, P. Vokac¹²⁷, G. Volpi⁴⁷, M. Volpi⁸⁶,
G.: Volpini^89a, H. von der Schmitt⁹⁹, H. von Radziewski⁴⁸, E. von Toerne²¹, V. Vorobel¹²⁶, V. Vorwerk¹², M. Vos¹⁶⁷,
R.: Voss³⁰, T.T. Voss¹⁷⁵, J.H. Vossebeld⁷³, N. Vranjes¹³⁶, M. Vranjes Milosavljevic¹⁰⁵, V. Vrba¹²⁵, M. Vreeswijk¹⁰⁵,
T.: Vu Anh⁴⁸, R. Vuillermet³⁰, I. Vukotic³¹, W. Wagner¹⁷⁵, P. Wagner¹²⁰, H. Wahlen¹⁷⁵, S. Wahrmund⁴⁴,
J.: Wakabayashi¹⁰¹, S. Walch⁸⁷, J. Walder⁷¹, R. Walker⁹⁸, W. Walkowiak¹⁴¹, R. Wall¹⁷⁶, P. Waller⁷³, B. Walsh¹⁷⁶,
C.: Wang⁴⁵, F. Wang¹⁷³, H. Wang¹⁷³, H. Wang^{^33b^,^ak}, J. Wang¹⁵¹, J. Wang⁵⁵, R. Wang¹⁰³, S.M. Wang¹⁵¹, T. Wang²¹,
A.: Warburton⁸⁵, C.P. Ward²⁸, D.R. Wardrope⁷⁷, M. Warsinsky⁴⁸, A. Washbrook⁴⁶, C. Wasicki⁴², I. Watanabe⁶⁶,

P.M. Watkins¹⁸, A.T. Watson¹⁸, I.J. Watson¹⁵⁰, M.F. Watson¹⁸, G. Watts¹³⁸, S. Watts⁸², A.T. Waugh¹⁵⁰,

B.M.: Waugh⁷⁷, M.S. Weber¹⁷, P. Weber⁵⁴, J.S. Webster³¹, A.R. Weidberg¹¹⁸, P. Weigell⁹⁹, J. Weingarten⁵⁴,
C.: Weiser⁴⁸, P.S. Wells³⁰, T. Wenaus²⁵, D. Wendland¹⁶, Z. Weng^{¹⁵¹^,^u}, T. Wengler³⁰, S. Wenig³⁰, N. Wermes²¹,
M.: Werner⁴⁸, P. Werner³⁰, M. Werth¹⁶³, M. Wessels^58a, J. Wetter¹⁶¹, C. Weydert⁵⁵, K. Whalen²⁹,

S.J.: Wheeler-Ellis¹⁶³, A. White⁸, M.J. White⁸⁶, S. White^{^122a^,^122b}, S.R. Whitehead¹¹⁸, D. Whiteson¹⁶³,
D.: Whittington⁶⁰, F. Wicek¹¹⁵, D. Wicke¹⁷⁵, F.J. Wickens¹²⁹, W. Wiedenmann¹⁷³, M. Wielers¹²⁹, P. Wienemann²¹,
C.: Wiglesworth⁷⁵, L.A.M. Wiik-Fuchs⁴⁸, P.A. Wijeratne⁷⁷, A. Wildauer⁹⁹, M.A. Wildt^{⁴²^,^r}, I. Wilhelm¹²⁶,

H.G. Wilkens³⁰, J.Z. Will⁹⁸, E. Williams³⁵, H.H. Williams¹²⁰, W. Willis³⁵, S. Willocq⁸⁴, J.A. Wilson¹⁸,

M.G. Wilson¹⁴³, A. Wilson⁸⁷, I. Wingerter-Seez⁵, S. Winkelmann⁴⁸, F. Winklmeier³⁰, M. Wittgen¹⁴³,

S.J. Wollstadt⁸¹, M.W. Wolter³⁹, H. Wolters^{^124a^,^h}, W.C. Wong⁴¹, G. Wooden⁸⁷, B.K. Wosiek³⁹, J. Wotschack³⁰,

M.J.: Woudstra⁸², K.W. Wozniak³⁹, K. Wraight⁵³, M. Wright⁵³, B. Wrona⁷³, S.L. Wu¹⁷³, X. Wu⁴⁹, Y. Wu^{^33b^,^al},
E.: Wulf³⁵, B.M. Wynne⁴⁶, S. Xella³⁶, M. Xiao¹³⁶, S. Xie⁴⁸, C. Xu^{^33b^,^z}, D. Xu¹³⁹, B. Yabsley¹⁵⁰, S. Yacoob^{^145a^,^am},
M.: Yamada⁶⁵, H. Yamaguchi¹⁵⁵, Y. Yamaguchi¹⁵⁵, A. Yamamoto⁶⁵, K. Yamamoto⁶³, S. Yamamoto¹⁵⁵,
T.: Yamamura¹⁵⁵, T. Yamanaka¹⁵⁵, T. Yamazaki¹⁵⁵, Y. Yamazaki⁶⁶, Z. Yan²², H. Yang⁸⁷, H. Yang¹⁷³, U.K. Yang⁸²,
Y.: Yang¹⁰⁹, Z. Yang^{^146a^,^146b}, S. Yanush⁹¹, L. Yao^33a, Y. Yao¹⁵, Y. Yasu⁶⁵, G.V. Ybeles Smit¹³⁰, J. Ye⁴⁰, S. Ye²⁵,
M.: Yilmaz^4c, R. Yoosoofmiya¹²³, K. Yorita¹⁷¹, R. Yoshida⁶, K. Yoshihara¹⁵⁵, C. Young¹⁴³, C.J. Young¹¹⁸,
S.: Youssef²², D. Yu²⁵, J. Yu⁸, J. Yu¹¹², L. Yuan⁶⁶, A. Yurkewicz¹⁰⁶, M. Byszewski³⁰, B. Zabinski³⁹, R. Zaidan⁶²,

A.M.: Zaitsev¹²⁸, Z. Zajacova³⁰, L. Zanello^{^132a^,^132b}, D. Zanzi⁹⁹, A. Zaytsev²⁵, C. Zeitnitz¹⁷⁵, M. Zeman¹²⁵,
A.: Zemla³⁹, C. Zendler²¹, O. Zenin¹²⁸, T. ^ˇs^144a, Z. Zinonos^{^122a^,^122b}, D. Zerwas¹¹⁵, G. Zevi della Porta⁵⁷

Zeniˇ,

D. Zhang^{^33b^,^ak}, H. Zhang⁸⁸, J. Zhang⁶, X. Zhang^33d, Z. Zhang¹¹⁵, L. Zhao¹⁰⁸, Z. Zhao^33b, A. Zhemchugov⁶⁴,

J. Zhong¹¹⁸, B. Zhou⁸⁷, N. Zhou¹⁶³, Y. Zhou¹⁵¹, C.G. Zhu^33d, H. Zhu⁴², J. Zhu⁸⁷, Y. Zhu^33b, X. Zhuang⁹⁸,

V. Zhuravlov⁹⁹, D. Zieminska⁶⁰, N.I. Zimin⁶⁴, R. Zimmermann²¹, S. Zimmermann²¹, S. Zimmermann⁴⁸, M. Ziolkowski¹⁴¹, R. Zitoun⁵, L. ^ˇc³⁵, V.V. Zmouchko^{¹²⁸^,^∗}, G. Zobernig¹⁷³, A. Zoccoli^{^20a^,^20b}

Zivkovi´,

M. zur Nedden¹⁶, V. Zutshi¹⁰⁶, L. Zwalinski³⁰.

¹School of Chemistry and Physics, University of Adelaide, Adelaide, Australia ²Physics Department, SUNY Albany, Albany NY, United States of America ³Department of Physics, University of Alberta, Edmonton AB, Canada ^{⁴⁽^a⁾}Department of Physics, Ankara University, Ankara; ^{⁽^b⁾}Department of Physics, Dumlupinar University, Kutahya; ^{⁽^c⁾}Department of Physics, Gazi University, Ankara; ^{⁽^d⁾}Division of Physics, TOBB University of Economics and Technology, Ankara; ^{⁽^e⁾}Turkish Atomic Energy Authority, Ankara, Turkey ⁵LAPP, CNRS/IN2P3 and Universit´e de Savoie, Annecy-le-Vieux, France ⁶High Energy Physics Division, Argonne National Laboratory, Argonne IL, United States of America ⁷Department of Physics, University of Arizona, Tucson AZ, United States of America ⁸Department of Physics, The University of Texas at Arlington, Arlington TX, United States of America ⁹Physics Department, University of Athens, Athens, Greece ¹⁰Physics Department, National Technical University of Athens, Zografou, Greece ¹¹Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan ¹²Institut de F´ısica d’Altes Energies and Departament de F´ısica de la Universitat Aut`onoma de Barcelona and ICREA, Barcelona, Spain ^{^{13 (}^a⁾}Institute of Physics, University of Belgrade, Belgrade; ^{⁽^b⁾}Vinca Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia ¹⁴Department for Physics and Technology, University of Bergen, Bergen, Norway ¹⁵Physics Division, Lawrence Berkeley National Laboratory and University of California, Berkeley CA, United States of America ¹⁶Department of Physics, Humboldt University, Berlin, Germany ¹⁷Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland ¹⁸School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom ^{^{19 (}^a⁾}Department of Physics, Bogazici University, Istanbul; ^{⁽^b⁾}Division of Physics, Dogus University, Istanbul; ^{⁽^c⁾}Department of Physics Engineering, Gaziantep University, Gaziantep; ^{⁽^d⁾}Department of Physics, Istanbul Technical University, Istanbul, Turkey ^{^{20 (}^a⁾}INFN Sezione di Bologna; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a di Bologna, Bologna, Italy ²¹Physikalisches Institut, University of Bonn, Bonn, Germany ²²Department of Physics, Boston University, Boston MA, United States of America ²³Department of Physics, Brandeis University, Waltham MA, United States of America ^{^{24 (}^a⁾}Universidade Federal do Rio De Janeiro COPPE/EE/IF, Rio de Janeiro; ^{⁽^b⁾}Federal University of Juiz de Fora (UFJF), Juiz de Fora; ^{⁽^c⁾}Federal University of Sao Joao del Rei (UFSJ), Sao Joao del Rei; ^{⁽^d⁾}Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, Brazil ²⁵Physics Department, Brookhaven National Laboratory, Upton NY, United States of America ^{^{26 (}^a⁾}National Institute of Physics and Nuclear Engineering, Bucharest; ^{⁽^b⁾}University Politehnica Bucharest, Bucharest; ^{⁽^c⁾}West University in Timisoara, Timisoara, Romania ²⁷Departamento de F´ısica, Universidad de Buenos Aires, Buenos Aires, Argentina ²⁸Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom ²⁹Department of Physics, Carleton University, Ottawa ON, Canada ³⁰CERN, Geneva, Switzerland ³¹Enrico Fermi Institute, University of Chicago, Chicago IL, United States of America ^{^{32 (}^a⁾}Departamento de F´ısica, Pontiﬁcia Universidad Cat´olica de Chile, Santiago; ^{⁽^b⁾}Departamento de F´ısica, Universidad T´ecnica Federico Santa Mar´ıa, Valpara´ıso, Chile ^{^{33 (}^a⁾}Institute of High Energy Physics, Chinese Academy of Sciences, Beijing; ^{⁽^b⁾}Department of Modern Physics, University of Science and Technology of China, Anhui; ^{⁽^c⁾}Department of Physics, Nanjing University, Jiangsu; ^{⁽^d⁾}School of Physics, Shandong University, Shandong, China ³⁴Laboratoire de Physique Corpusculaire, Clermont Universit´e Blaise Pascal and CNRS/IN2P3,

e and Universit´Clermont-Ferrand, France ³⁵Nevis Laboratory, Columbia University, Irvington NY, United States of America ³⁶Niels Bohr Institute, University of Copenhagen, Kobenhavn, Denmark ^{^{37 (}^a⁾}INFN Gruppo Collegato di Cosenza; ^{⁽^b⁾}Dipartimento di Fisica, Universit`

a della Calabria, Arcavata di Rende, Italy ³⁸AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland ³⁹The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland ⁴⁰Physics Department, Southern Methodist University, Dallas TX, United States of America ⁴¹Physics Department, University of Texas at Dallas, Richardson TX, United States of America ⁴²DESY, Hamburg and Zeuthen, Germany ⁴³Institut f¨ur Experimentelle Physik IV, Technische Universit¨at Dortmund, Dortmund, Germany ⁴⁴Institut f¨

ur Kern-und Teilchenphysik, Technical University Dresden, Dresden, Germany ⁴⁵Department of Physics, Duke University, Durham NC, United States of America ⁴⁶SUPA -School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom ⁴⁷INFN Laboratori Nazionali di Frascati, Frascati, Italy ⁴⁸Fakult¨at f¨ur Mathematik und Physik, Albert-Ludwigs-Universit¨at, Freiburg, Germany ⁴⁹Section de Physique, Universit´eve, Geneva, Switzerland

e de Gen`^{^{50 (}^a⁾}INFN Sezione di Genova; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a di Genova, Genova, Italy ^{^{51 (}^a⁾}E. Andronikashvili Institute of Physics, Tbilisi State University, Tbilisi; ^{⁽^b⁾}High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia ⁵²II Physikalisches Institut, Justus-Liebig-Universit¨at Giessen, Giessen, Germany ⁵³SUPA -School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom ⁵⁴II Physikalisches Institut, Georg-August-Universit¨at, G¨ottingen, Germany ⁵⁵Laboratoire de Physique Subatomique et de Cosmologie, Universit´e Joseph Fourier and CNRS/IN2P3 and Institut National Polytechnique de Grenoble, Grenoble, France ⁵⁶Department of Physics, Hampton University, Hampton VA, United States of America ⁵⁷Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge MA, United States of America ^{^{58 (}^a⁾}Kirchhoﬀ-Institut f¨at Heidelberg, Heidelberg; ^{⁽^b⁾}Physikalisches Institut,

ur Physik, Ruprecht-Karls-Universit¨Ruprecht-Karls-Universit¨at Heidelberg, Heidelberg; ^{⁽^c⁾}ZITI Institut f¨ur technische Informatik, Ruprecht-Karls-Universit¨

at Heidelberg, Mannheim, Germany ⁵⁹Faculty of Applied Information Science, Hiroshima Institute of Technology, Hiroshima, Japan ⁶⁰Department of Physics, Indiana University, Bloomington IN, United States of America ⁶¹Institut f¨at, Innsbruck, Austria

ur Astro-und Teilchenphysik, Leopold-Franzens-Universit¨⁶²University of Iowa, Iowa City IA, United States of America ⁶³Department of Physics and Astronomy, Iowa State University, Ames IA, United States of America ⁶⁴Joint Institute for Nuclear Research, JINR Dubna, Dubna, Russia ⁶⁵KEK, High Energy Accelerator Research Organization, Tsukuba, Japan ⁶⁶Graduate School of Science, Kobe University, Kobe, Japan ⁶⁷Faculty of Science, Kyoto University, Kyoto, Japan ⁶⁸Kyoto University of Education, Kyoto, Japan ⁶⁹Department of Physics, Kyushu University, Fukuoka, Japan ⁷⁰Instituto de F´ısica La Plata, Universidad Nacional de La Plata and CONICET, La Plata, Argentina ⁷¹Physics Department, Lancaster University, Lancaster, United Kingdom ^{^{72 (}^a⁾}INFN Sezione di Lecce; ^{⁽^b⁾}Dipartimento di Matematica e Fisica, Universit`

a del Salento, Lecce, Italy ⁷³Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom ⁷⁴Department of Physics, Joˇ

zef Stefan Institute and University of Ljubljana, Ljubljana, Slovenia ⁷⁵School of Physics and Astronomy, Queen Mary University of London, London, United Kingdom ⁷⁶Department of Physics, Royal Holloway University of London, Surrey, United Kingdom ⁷⁷Department of Physics and Astronomy, University College London, London, United Kingdom ⁷⁸Laboratoire de Physique Nucl´eaire et de Hautes Energies, UPMC and Universit´e Paris-Diderot and CNRS/IN2P3, Paris, France ⁷⁹Fysiska institutionen, Lunds universitet, Lund, Sweden ⁸⁰Departamento de Fisica Teorica C-15, Universidad Autonoma de Madrid, Madrid, Spain ⁸¹Institut f¨ur Physik, Universit¨at Mainz, Mainz, Germany ⁸²School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom ⁸³CPPM, Aix-Marseille Universit´

e and CNRS/IN2P3, Marseille, France

⁸⁴Department of Physics, University of Massachusetts, Amherst MA, United States of America

⁸⁵Department of Physics, McGill University, Montreal QC, Canada

⁸⁶School of Physics, University of Melbourne, Victoria, Australia

⁸⁷Department of Physics, The University of Michigan, Ann Arbor MI, United States of America

⁸⁸Department of Physics and Astronomy, Michigan State University, East Lansing MI, United States of America

^{^{89 (}^a⁾}INFN Sezione di Milano; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a di Milano, Milano, Italy

⁹⁰B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Republic of Belarus

⁹¹National Scientiﬁc and Educational Centre for Particle and High Energy Physics, Minsk, Republic of Belarus

⁹²Department of Physics, Massachusetts Institute of Technology, Cambridge MA, United States of America

⁹³Group of Particle Physics, University of Montreal, Montreal QC, Canada

⁹⁴P.N. Lebedev Institute of Physics, Academy of Sciences, Moscow, Russia

⁹⁵Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia

⁹⁶Moscow Engineering and Physics Institute (MEPhI), Moscow, Russia

⁹⁷Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia

⁹⁸Fakult¨at f¨ur Physik, Ludwig-Maximilians-Universit¨at M¨unchen, M¨unchen, Germany

⁹⁹Max-Planck-Institut f¨unchen, Germany

ur Physik (Werner-Heisenberg-Institut), M¨

¹⁰⁰Nagasaki Institute of Applied Science, Nagasaki, Japan

¹⁰¹Graduate School of Science and Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Japan

^{^{102 (}^a⁾}INFN Sezione di Napoli; ^{⁽^b⁾}Dipartimento di Scienze Fisiche, Universit`a di Napoli, Napoli, Italy

¹⁰³Department of Physics and Astronomy, University of New Mexico, Albuquerque NM, United States of America

¹⁰⁴Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen,

Netherlands

¹⁰⁵Nikhef National Institute for Subatomic Physics and University of Amsterdam, Amsterdam, Netherlands

¹⁰⁶Department of Physics, Northern Illinois University, DeKalb IL, United States of America

¹⁰⁷Budker Institute of Nuclear Physics, SB RAS, Novosibirsk, Russia

¹⁰⁸Department of Physics, New York University, New York NY, United States of America

¹⁰⁹Ohio State University, Columbus OH, United States of America

¹¹⁰Faculty of Science, Okayama University, Okayama, Japan

¹¹¹Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman OK, United States of

America

¹¹²Department of Physics, Oklahoma State University, Stillwater OK, United States of America

¹¹³Palack´y University, RCPTM, Olomouc, Czech Republic

¹¹⁴Center for High Energy Physics, University of Oregon, Eugene OR, United States of America

¹¹⁵LAL, Universit´e Paris-Sud and CNRS/IN2P3, Orsay, France

¹¹⁶Graduate School of Science, Osaka University, Osaka, Japan

¹¹⁷Department of Physics, University of Oslo, Oslo, Norway

¹¹⁸Department of Physics, Oxford University, Oxford, United Kingdom

^{^{119 (}^a⁾}INFN Sezione di Pavia; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a di Pavia, Pavia, Italy

¹²⁰Department of Physics, University of Pennsylvania, Philadelphia PA, United States of America

¹²¹Petersburg Nuclear Physics Institute, Gatchina, Russia

^{^{122 (}^a⁾}INFN Sezione di Pisa; ^{⁽^b⁾}Dipartimento di Fisica E. Fermi, Universit`a di Pisa, Pisa, Italy

¹²³Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh PA, United States of America

^{^{124 (}^a⁾}Laboratorio de Instrumentacao e Fisica Experimental de Particulas -LIP, Lisboa, Portugal; ^{⁽^b⁾}Departamento de

Fisica Teorica y del Cosmos and CAFPE, Universidad de Granada, Granada, Spain

¹²⁵Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic

¹²⁶Faculty of Mathematics and Physics, Charles University in Prague, Praha, Czech Republic

¹²⁷Czech Technical University in Prague, Praha, Czech Republic

¹²⁸State Research Center Institute for High Energy Physics, Protvino, Russia

¹²⁹Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom ¹³⁰Physics Department, University of Regina, Regina SK, Canada ¹³¹Ritsumeikan University, Kusatsu, Shiga, Japan ^{^{132 (}^a⁾}INFN Sezione di Roma I; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a La Sapienza, Roma, Italy

^{^{133 (}^a⁾}INFN Sezione di Roma Tor Vergata; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a di Roma Tor Vergata, Roma, Italy

^{^{134 (}^a⁾}INFN Sezione di Roma Tre; ^{⁽^b⁾}Dipartimento di Fisica, Universit`a Roma Tre, Roma, Italy

^{^{135 (}^a⁾}Facult´e des Sciences Ain Chock, R´eseau Universitaire de Physique des Hautes Energies -Universit´e Hassan II,

Casablanca; ^{⁽^b⁾}Centre National de l’Energie des Sciences Techniques Nucleaires, Rabat; ^{⁽^c⁾}Facult´e des Sciences

Semlalia, Universit´e des Sciences, Universit´e Cadi Ayyad, LPHEA-Marrakech; ^{⁽^d⁾}Facult´e Mohamed Premier and

LPTPM, Oujda; ^{⁽^e⁾}Facult´e des sciences, Universit´e Mohammed V-Agdal, Rabat, Morocco

¹³⁶DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de l’Univers), CEA Saclay (Commissariat a

l’Energie Atomique), Gif-sur-Yvette, France

¹³⁷Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz CA, United States of

America

¹³⁸Department of Physics, University of Washington, Seattle WA, United States of America

¹³⁹Department of Physics and Astronomy, University of Sheﬃeld, Sheﬃeld, United Kingdom

¹⁴⁰Department of Physics, Shinshu University, Nagano, Japan

¹⁴¹Fachbereich Physik, Universit¨at Siegen, Siegen, Germany

¹⁴²Department of Physics, Simon Fraser University, Burnaby BC, Canada

¹⁴³SLAC National Accelerator Laboratory, Stanford CA, United States of America

^{^{144 (}^a⁾}Faculty of Mathematics, Physics & Informatics, Comenius University, Bratislava; ^{⁽^b⁾}Department of Subnuclear

Physics, Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovak Republic

^{^{145 (}^a⁾}Department of Physics, University of Johannesburg, Johannesburg; ^{⁽^b⁾}School of Physics, University of the

Witwatersrand, Johannesburg, South Africa

^{^{146 (}^a⁾}Department of Physics, Stockholm University; ^{⁽^b⁾}The Oskar Klein Centre, Stockholm, Sweden

¹⁴⁷Physics Department, Royal Institute of Technology, Stockholm, Sweden

¹⁴⁸Departments of Physics & Astronomy and Chemistry, Stony Brook University, Stony Brook NY, United States of

America

¹⁴⁹Department of Physics and Astronomy, University of Sussex, Brighton, United Kingdom

¹⁵⁰School of Physics, University of Sydney, Sydney, Australia

¹⁵¹Institute of Physics, Academia Sinica, Taipei, Taiwan

¹⁵²Department of Physics, Technion: Israel Institute of Technology, Haifa, Israel

¹⁵³Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel

¹⁵⁴Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece

¹⁵⁵International Center for Elementary Particle Physics and Department of Physics, The University of Tokyo, Tokyo,

Japan

¹⁵⁶Graduate School of Science and Technology, Tokyo Metropolitan University, Tokyo, Japan

¹⁵⁷Department of Physics, Tokyo Institute of Technology, Tokyo, Japan

¹⁵⁸Department of Physics, University of Toronto, Toronto ON, Canada

^{^{159 (}^a⁾}TRIUMF, Vancouver BC; ^{⁽^b⁾}Department of Physics and Astronomy, York University, Toronto ON, Canada

¹⁶⁰Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan

¹⁶¹Department of Physics and Astronomy, Tufts University, Medford MA, United States of America

¹⁶²Centro de Investigaciones, Universidad Antonio Narino, Bogota, Colombia

¹⁶³Department of Physics and Astronomy, University of California Irvine, Irvine CA, United States of America

^{^{164 (}^a⁾}INFN Gruppo Collegato di Udine; ^{⁽^b⁾}ICTP, Trieste; ^{⁽^c⁾}Dipartimento di Chimica, Fisica e Ambiente, Universit`a

di Udine, Udine, Italy

¹⁶⁵Department of Physics, University of Illinois, Urbana IL, United States of America

¹⁶⁶Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden

¹⁶⁷Instituto de F´ısica Corpuscular (IFIC) and Departamento de F´omica, Molecular y Nuclear and ısica At´

Departamento de Ingenier´ıa Electr´onica and Instituto de Microelectr´onica de Barcelona (IMB-CNM), University of

Valencia and CSIC, Valencia, Spain

¹⁶⁸Department of Physics, University of British Columbia, Vancouver BC, Canada

¹⁶⁹Department of Physics and Astronomy, University of Victoria, Victoria BC, Canada ¹⁷⁰Department of Physics, University of Warwick, Coventry, United Kingdom ¹⁷¹Waseda University, Tokyo, Japan ¹⁷²Department of Particle Physics, The Weizmann Institute of Science, Rehovot, Israel ¹⁷³Department of Physics, University of Wisconsin, Madison WI, United States of America ¹⁷⁴Fakult¨ur Physik und Astronomie, Julius-Maximilians-Universit¨urzburg, Germany

atf¨at,W¨¹⁷⁵Fachbereich C Physik, Bergische Universit¨at Wuppertal, Wuppertal, Germany ¹⁷⁶Department of Physics, Yale University, New Haven CT, United States of America ¹⁷⁷Yerevan Physics Institute, Yerevan, Armenia ¹⁷⁸Centre de Calcul de l’Institut National de Physique Nucl´eaire et de Physique des Particules (IN2P3), Villeurbanne, France ^aAlso at Laboratorio de Instrumentacao e Fisica Experimental de Particulas -LIP, Lisboa, Portugal ^bAlso at Faculdade de Ciencias and CFNUL, Universidade de Lisboa, Lisboa, Portugal ^cAlso at Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom ^dAlso at TRIUMF, Vancouver BC, Canada ^eAlso at Department of Physics, California State University, Fresno CA, United States of America ^fAlso at Novosibirsk State University, Novosibirsk, Russia ^gAlso at Fermilab, Batavia IL, United States of America ^hAlso at Department of Physics, University of Coimbra, Coimbra, Portugal ⁱAlso at Department of Physics, UASLP, San Luis Potosi, Mexico ^jAlso at Universit`a di Napoli Parthenope, Napoli, Italy ^kAlso at Institute of Particle Physics (IPP), Canada ^lAlso at Department of Physics, Middle East Technical University, Ankara, Turkey ^mAlso at Louisiana Tech University, Ruston LA, United States of America ⁿAlso at Dep Fisica and CEFITEC of Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal

^oAlso at Department of Physics and Astronomy, University College London, London, United Kingdom ^pAlso at Department of Physics, University of Cape Town, Cape Town, South Africa ^qAlso at Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan ^rAlso at Institut f¨at Hamburg, Hamburg, Germany

ur Experimentalphysik, Universit¨^sAlso at Manhattan College, New York NY, United States of America ^tAlso at CPPM, Aix-Marseille Universit´e and CNRS/IN2P3, Marseille, France ^uAlso at School of Physics and Engineering, Sun Yat-sen University, Guanzhou, China ^vAlso at Academia Sinica Grid Computing, Institute of Physics, Academia Sinica, Taipei, Taiwan ^wAlso at Laboratoire de Physique Nucl´eaire et de Hautes Energies, UPMC and Universit´e Paris-Diderot and CNRS/IN2P3, Paris, France ^xAlso at School of Physics, Shandong University, Shandong, China ^yAlso at Dipartimento di Fisica, Universit`

a La Sapienza, Roma, Italy

^zAlso at DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de l’Univers), CEA Saclay (Commissariat a

l’Energie Atomique), Gif-sur-Yvette, France

^aaAlso at Section de Physique, Universit´eve, Geneva, Switzerland e de Gen`

^abAlso at Departamento de Fisica, Universidade de Minho, Braga, Portugal

^acAlso at Department of Physics and Astronomy, University of South Carolina, Columbia SC, United States of

America

^adAlso at Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Budapest, Hungary

^aeAlso at California Institute of Technology, Pasadena CA, United States of America

^afAlso at Institute of Physics, Jagiellonian University, Krakow, Poland

^agAlso at LAL, Universit´e Paris-Sud and CNRS/IN2P3, Orsay, France

^ahAlso at Nevis Laboratory, Columbia University, Irvington NY, United States of America

^aiAlso at Department of Physics and Astronomy, University of Sheﬃeld, Sheﬃeld, United Kingdom

^ajAlso at Department of Physics, Oxford University, Oxford, United Kingdom

^akAlso at Institute of Physics, Academia Sinica, Taipei, Taiwan

^alAlso at Department of Physics, The University of Michigan, Ann Arbor MI, United States of America

^amAlso at Discipline of Physics, University of KwaZulu-Natal, Durban, South Africa

∗ Deceased

EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)

Observation of a New Particle in the Search for the Standard Model Higgs Boson with the ATLAS Detector at the LHC

Observation of a New Particle in the Search for the Standard Model Higgs Boson with the ATLAS Detector at the LHC

4.1. Event selection

4.2. Background estimation

4.3. Systematic uncertainties

5.1. Event selection

5.2. Invariant mass reconstruction

5.3. Event categorisation

5.4. Signal modelling

5.5. Background modelling

5.6. Systematic uncertainties

5.7. Results

6.1. Event selection

6.2. Background normalisation and control samples

6.2.1. W+jets background estimation

6.2.2. Top control sample

6.3. Systematic uncertainties

6.4. Results

9.1. Excluded mass regions

9.2. Observation of an excess of events

9.3. Characterising the excess

126.0 ± 0.4 (stat) ± 0.4 (sys) GeV.

The ATLAS Collaboration