
\section{The Canadian CDF-II Physics Program (new grant)}

\subsection{Top Quark Physics Studies}

\subsection{$W$ Boson Physics Studies}

\subsection{Exotics, QCD, and Higgs Physics Studies}


\section{First Physics from CDF-II (last grant)}

CDF has a very broad physics program pursued on four main fronts: QCD
measurements, heavy quark production and decay, exploration of the
energy frontier searching for physics beyond the Standard Model and
precision top and electroweak measurements. During the last year,
significant progress was made on all these fronts and preliminary
results were presented at the summer 2003 conferences using a data sample
that is now comparable to our Run I dataset. We summarise the
highlights below.

\subsection{QCD and Heavy Quark Production}

The center of mass energy of $p\bar{p}$ collisions at the Tevatron is
$\sim$10\% higher in Run II than it was in Run I.  This modest
increase translates into much larger cross sections for high $Q^2$
processes.  For example, NLO QCD calculations predict that the production
cross section for jets of transverse energy above 400 GeV should be
twice what they were at the lower centre of mass energy of Run I.  
Figure~\ref{fig:jets}a) shows the inclusive jet
cross section using 177 pb$^{-1}$ of run II data. Within the estimated
uncertainties, the data is consistent with NLO calculations.  
This dataset contains the highest transverse energy jets ever
observed, 150 GeV beyond the highest energy jets seen in Run I.

The $B$ physics programme relies on this very high QCD quark pair
production rate and on efficient triggers.  In particular, CDF
benefits greatly from a new displaced track trigger that provides very
large samples of hadronic $B$ decays.  This trigger also opens up a
rich charm physics programme as evidenced by CDF's very early Run II
papers on the production of charm mesons.  The first of these measured
the $D^+ - D_s^+$ mass difference to be $(99.41 \pm 0.38 [{\rm stat}]
\pm 0.21 [{\rm sys}])$ MeV/c$^2$.  CDF's unique ${\Lambda}_b$ and
$B_s^0$ programme is also making an impact on the field with the first
observations of $B_s^0 \rightarrow K^+ K^-$, $B_s^0 \rightarrow D_s^+
\pi^-$, and ${\Lambda}_b^0
\rightarrow {\Lambda}_c^+ \pi^-$ (shown in Figure~\ref{fig:jets} b)).

\subsection{Physics Beyond the Standard Model}

Searches for exotic $B$ decays have also been
performed. CDF has searched for the flavour changing neutral current
reactions $B_s^0 \rightarrow \mu^+ \mu^-$ and $B^0 \rightarrow \mu^+
\mu^+$. The branching ratio for the $B_s^0$ signature is expected to
be on the order of $\sim 4 \times 10^{-9}$ in the Standard
Model. However, in some SUSY models, this branching ratio can be up to
a 1000 times larger.  CDF's result, the world's best limit for ${\cal
B} (B_s^0 \rightarrow \mu^+ \mu^-)$, is now $<$ $9.5 \times 10^{-7}$
at 95\% confidence level (CL).
  
The increase in the Tevatron center of mass energy mentioned previously also
allows CDF to significantly improve our reach for heavy exotic
objects. In particular, our world's best mass limit on direct searches
for a $Z$' boson has been improved by studying the production rate of
high mass, opposite charge, same flavour di-leptons. The new 95\%
CL limit on $m_{Z'}$, which assumes $Z'$ couplings to
leptons equal to those of the Standard Model $Z$ boson, is 730
GeV/c$^2$. This signature has also been used to set new limits on
Randall Sundrum gravitons.


\begin{figure}
%\epsfig{file=incljets.pdf,height=2.6in}
\hskip 0.3in
%\epsfig{file=lamb.pdf,height=2.6in}
\caption{a) [left] The inclusive jet cross section measured at 2.0 TeV. 
b) [right] CDF-II's signal for $\Lambda_b^0$ decaying hadronically. }
\label{fig:jets}
\end{figure}

\subsection{Precision Electroweak and Top Physics}
 
The electroweak programme is now well under way with upcoming
publications of the $Z$ and $W$ boson production cross sections and
the measurement of the forward-backward asymmetry in $Z$ boson decays.
Recent Run II results include a determination of the $WW$ cross
section of $(5.1 \pm 4.5[{\rm stat}] \pm 1.3[{\rm sys}] \pm 0.3[{\rm
lumi}])$ pb and the $W\gamma$ cross section $(17.2 \pm 1.8[{\rm stat}]
\pm 2.2[{\rm sys}] \pm 1.0[{\rm lumi}])$ pb. These are to be compared
with the next-to-leading-order (NLO) Standard Model predictions of: $(13.5
\pm 0.3)$ pb and $(18.6 \pm 1.3)$ pb, respectively.  These
measurements are important tests of electroweak triple gauge boson
couplings.  We have also looked at the presence of anomalous couplings
in the $Z\gamma$ channel by comparing the measured cross section of
$(5.8 \pm 1.0[{\rm stat}]
\pm 0.4[{\rm sys}] \pm 0.4[{\rm lumi}])$ pb to the Standard Model
expectation and found good agreement within the estimated
uncertainties.  The presentation of the first $W$ mass measurement
results are planned for early 2004.

Much remains to be discovered about the top quark given the relatively
small samples collected in Run I.  The current Run II dataset more
than doubles the world's previous top quark sample and we will soon be
in a position to perform precision measurements of this exotic
particle.  Measurements of the $t\bar{t}$ production cross section
were presented during the summer of 2003 for the dilepton and lepton +
jets final states. Two analyses focused on the dilepton decay
channel. The first analysis followed closely the selections previously
used in Run I and has a higher $S/B$ ratio.  The second analysis only
looked for an isolated track as its second lepton candidate, thus
providing a higher acceptance overall and to $\tau$ leptons in
particular.  The analyses reported cross sections of $(7.6 \pm
3.5[{\rm stat}] \pm 1.5[{\rm sys}])$ pb and $(7.3 \pm 3.4[{\rm stat}]
\pm 1.7[{\rm sys}])$ pb, respectively.  A Standard Model NLO
calculation gives $(6.7 \pm 0.8)$ pb.  The measurement of the
$t\bar{t}$ cross section was also performed in the lepton + jets final
state, using a kinematic fit to the $H_T$ distribution resulting in a
value of $(7.1 \pm 2.4[{\rm stat}] \pm 3.0[{\rm sys}])$ pb. All
measurements are consistent with each other and with SM expectations.
The top quark mass was also measured is both dilepton and lepton +
jets channels and the results are consistent with the current world
average but with systematic uncertainties that are higher than those
obtained in Run I.  We expect these uncertainties to be significantly
reduced in the coming year as our understanding of the calorimeters
improve.


\section{CDF-II Physics in Canada (last grant)}

The breadth of the CDF physics program described in the previous
section is mirrored in the physics topics being studied by members of
the IPP group. We are making significant contributions in top
measurements, precision electroweak measurements, searches for New
Physics and QCD measurements, as detailed in the sections below.

\subsection{IPP Top Quark Physics Studies}
\label{sect:top}

Since the discovery of the top quark, emphasis has turned to the
precise characterization of its properties; prior to Run~II, however,
this effort was hampered by statistical limitations.  The CDF Run~II
upgrades have enhanced the top quark yield per unit of time-integrated
luminosity by both extending and improving the lepton identification
systems, and by significantly improving the bottom quark tagging
capability.  Combined with the additional time-integrated luminosity
and the higher cross section afforded by the increase in
centre-of-mass energy from 1.8 to 2.0~TeV, we will soon be able to
study samples of several hundred top-quark candidates.

With an initial data sample corresponding to a time-integrated
luminosity of $\sim$108~pb$^{-1}$ from early Run~II datataking,
members of our IPP group (Arguin, Sabik, Savard, and Sinervo) have
performed a preliminary top-mass measurement in the lepton~+~jets
channel.  Both top quarks decay into $b$-quark jets: for the
lepton~+~jets channel, in one case the decay is semileptonic whereas
the $W$ boson from the second top quark decays hadronically, giving a
topology of one lepton and four jets, two of which are $b$-quark jets.
Figure~\ref{fig:mtop}a) plots the reconstructed mass distribution of
the 22 $t\bar{t}$ candidate events found where 3 of the 4 jets satisfy
a transverse energy requirement of $E_T > 15$~GeV, the fourth jet
satisfies a cut of $E_T > 8$~GeV, and one of the jets is tagged as a
$b$ quark.  A major component of the lepton~+~jets analysis,
contributed by our group, is a set of top-specific jet-energy
corrections, corrections that account for fragmentation differences
between light-quark and $b$-quark jets, that are tuned to the non-flat
$p_T$ spectrum of jets from $t\bar{t}$ decay, and that supply the mass
reconstruction fitting machinery with top-specific jet-energy
resolutions.  Our analysis has provided a preliminary top mass
measurement of $(177.5\, ^{+12.7}_{\phantom{1}-9.4}[{\rm stat}]\pm
7.1[{\rm syst}])$~GeV/$c^2$.

\begin{figure}
\begin{center}
%\epsfig{figure=final_plot_84jfcombo.pdf,height=2.0in}
\hskip 0.3in
%\epsfig{figure=Ht_fitresult_data.pdf,height=2.0in}
\end{center}
\caption{ a) [left] The reconstructed top mass distribution plotted with the
  expected distributions from the Monte Carlo signal template at the
  fit mass and the background template.  The inset figure shows the
  corresponding $-\Delta\ln(L)$ distribution. b) [right] The $H_T$ (or
  scalar $\Sigma E_T$ over all jets, lepton, and \MEt\ in the event)
  distribution for 107~pb$^{-1}$ of Run-II data, with smoothed Monte
  Carlo templates representing calculated contributions for single top
  signal and backgrounds.  The $H_T$ variable is used because both the
  $s$-channel and $t$-channel single-top processes, which are combined
  in the figure, exhibit similar distributions in this quantity.}
\label{fig:mtop}
\end{figure}


Whereas the discovery of the top quark was made possible by observing
$t\bar{t}$ pairs produced via the strong interaction, single top
quarks can also be produced at the Tevatron by electroweak processes.
The cross section of a virtual $W^*$ propagator decaying into a top
and bottom quark is proportional to the CKM matrix element $\left|
V_{tb} \right|^2$ and has sensitivity to non-standard couplings of the
top quark, making it an ideal observable in our search to uncover new
physics.  IPP researchers Kordas, Savard, B.~Stelzer, and
Trischuk have conducted a preliminary search for single-top
production.  Results are illustrated in Figure~\ref{fig:mtop}b), and
an upper limit on the single top production cross section has
been found to be 15.4~pb at 95\% CL.

New avenues of inquiry into top physics are also being explored.
Savard and Tafirout are developing techniques to measure the
$t\bar{t}$ production cross section in the dilepton channel with
greater acceptance using a sample with tight cuts on one lepton
candidate and isolated-track criteria on the other.  A preliminary
$t\bar{t}$ cross section of $(7.4 \pm 3.4 [{\rm stat.}]\pm 1.7[{\rm
  syst.}])$~pb has been obtained.  A second, highly challenging,
analysis is seeking to study $t\bar{t}$ production characteristics,
specifically the ratio of $t\bar{t}$ cross section due to gluon-gluon
fusion to that due to quark-antiquark annihilation.  Pashapour and
Sinervo are investigating techniques and variables to discriminate
between the two production mechanisms by examining
initial-state gluon radiation properties while minimizing model
dependence.

\subsection{IPP $W$ Boson Physics Studies}

A precise mass measurement of the $W$ boson, by virtue of the fact
that its mass and that of the top quark are connected to the Higgs
boson mass through radiative corrections, can help to provide both
constraints on the Higgs mass and a valuable consistency check of the
Standard Model.  The $W$ mass is also sensitive to new physics from
exotic particles populating loops in the $W$ propagator.

Members of our IPP group (O.~Stelzer-Chilton, Trischuk and Vollrath)
are conducting a measurement of the $W$-boson mass using candidates in
the $W \to \mu\nu_\mu$ channel to form the transverse mass ($m_T$)
distribution shown in Figure~\ref{fig:trans_mass_W}.  For this
analysis the determination of the muon momentum scale is critical. We
have been heavily involved in understanding the tracker alignment and
calibrating the momentum scale using $J/\psi$ and $\Upsilon$ control
samples. Further, the $m_T$ distribution cannot be predicted
analytically, necessitating the use of Monte Carlo line shape
predictions.  Currently, no NLO QCD Monte Carlo
calculation includes ${\cal O}(\alpha)$ electroweak corrections.  Our
group is developing techniques to numerically merge the output from
the {\sc resbos} QCD generator with that from the {\sc wgrad/zgrad}
QED generator providing improving the understanding one of the few $W$
mass systematics that is not naturally reduced by having larger
statistics control samples.


\begin{figure}
\begin{center}
%\leavemode
\epsfxsize=4.0in
%\epsffile{w_mt_new.pdf}
\end{center}
\caption{Transverse mass distribution of $W\to\mu\nu_\mu$ candidates in
  72~pb$^{-1}$ of Run~II data.  The background sources (from
  $Z\to\mu\mu$, $W\to\tau\nu_\tau$, cosmic-ray, and QCD dijet
  processes) constitute a total of $\sim$11\% of the signal (shown
  in grey).}
\label{fig:trans_mass_W}
\end{figure}

\subsection{IPP Exotic, QCD, and Higgs Physics Studies}

The IPP group is exploring signatures for SUSY (MacQueen and Orr) in
searches for $R$-parity conserving supersymmetry signals using
jet~+~\MEt~signatures. So far their studies have focused on
instrumental backgrounds in multi-jet events with large missing
transverse energy. They have also been studying ways of establishing
signature based cross-section limits that do not depend on the details
of particular New Physics phenomena. Instead it is hoped that these
limits will be sufficiently general that they could be applied to
theories that have not yet been fully fleshed out -- without
necessitating a complete re-analysis of the CDF data.

The exciting possibility of detecting a light Higgs boson has been the
focus of much attention.  Double diffractive collisions, in which the
final state contains only intact protons that escape the central
detectors, could allow a precise measurement of the Higgs mass near
200~GeV using the missing mass method on protons tagged with Roman pot
detectors, far downstream of the interaction region.  While this
method, which applies only to exclusive Higgs production, is expected
to have a rate too low to be observable at the Tevatron, the inclusive
process has recently been estimated to be detectable. Hamilton and
Pinfold are investigating the use of the doubly diffractive channel as
a clean Higgs production environment, work that is expected to inform
similar searches in diffractive production at the LHC.

Intimately linked to searches for the Higgs boson in the low-mass
region, where the $H \to b\bar{b}$ mode dominates, is a deeper
understanding of QCD jets, in particular high-momentum $b$-quark jets.
Pairs of $b$ quarks can also be produced through purely QCD
interactions at rates orders of magnitude greater than those from
Standard Model Higgs decays; this underscores a need for well
understood $b$-quark production cross sections and QCD jet properties,
measurements which are being investigated by Snihur, Warburton and
Williams.  By demanding the presence of an associated $W$ boson, the
QCD background can be markedly reduced, and indeed the $Wb\bar{b}$
cross section is a promising avenue to setting the world's best lower
limit on the Higgs mass with CDF.\footnote{Note that this topology is
complementary to that for the single-top production described in
Section~\ref{sect:top}, where the $W^*\to t\bar{b}$ channel mimics the
associated $WH$ Higgs production final state.}  As a component of this
larger study we are analysing the inclusive $b$-quark production cross
section at high transverse momenta, especially interesting since
previous Tevatron and HERA measurements have consistently indicated
that current theoretical NLO QCD cross-section
calculations underestimate the observed cross sections at all values
of $b$-quark transverse momentum investigated.

Another enticing low-mass Higgs signature observable, under study by
Lai and Sinervo, is the $p\bar{p} \to t\bar{t}H$
final state.  Although the cross section for a Higgs mass of 120~GeV is
predicted to be only $\sim$4.8~fb, this mode's distinctive topology
and our own experience in top-quark physics will enable us to achieve
increased signal-to-background ratios and better characterise the backgrounds
in this channel -- that will be pursued further by LHC experiments.


\section{Tevatron Luminosity Program and Projected
Physics Reach (new grant)}

The early Run-II results that are currently entering publications are
primarily based on data samples having time-integrated luminosities of
$0.2 - 0.4$~fb$^{-1}$.  The delivered time-integrated luminosity for
Run~II is presently in excess of 1~fb$^{-1}$ and, at the time of this
writing, the Tevatron peak instantaneous luminosity record recently
exceeded $1.4 \times 10^{32}$~cm$^{-2}$s$^{-1}$.

At present datataking efficiencies of 85$-$90\%, and under the current
Tevatron accelerator performance, a minimum of 2~fb$^{-1}$ are
expected by 2007 and 4~fb$^{-1}$ by 2009, two doublings over the next
four years.  When considered beside both the data already collected
and these conservative luminosity projections, the data that have been
analysed to date represent less than one tenth of the Tevatron
program's baseline reach.  Factoring in planned upgrades to the
Tevatron accelerator complex, including electron cooling, three
integrated luminosity doublings are expected, {\it i.e.}, 4~fb$^{-1}$
by 2007 and 8~fb$^{-1}$ by 2009.  The following discusses selected
physics projections for Run~II of the Tevatron.

In the broad range of $B$ physics measurements possible at, and unique
to, the Tevatron, the study of $B_s$ mixing will contribute unique
testing of the flavour sector in the Standard Model.  When taking into
account improvements in existing analysis procedures, including kaon
tagging, additional channels, trigger adjustments, and a 20\%
improvement in vertex resolution, the Tevatron is expected to extend
sensitivity from a 95\% C.L. exclusion with 2~fb$^{-1}$, to 3$\sigma$
evidence with 4~fb$^{-1}$, to 5$\sigma$ discovery with 8~fb$^{-1}$.
Refer to Fig.~\ref{fig:Bs_mixing_projection.eps}.  The absence of a
discovery of $B_s$ mixing in 8~fb$^{-1}$ would represent a striking
contravention of the Standard Model, {\it i.e.}, new physics.

\begin{figure}
\begin{center}
%\leavemode
\epsfxsize=2.5in
\epsffile{Bs_mixing_projection.eps}
\end{center}
\caption{The Tevatron $B_s$ mixing 5$\sigma$ discovery projection,
as a function of delivered luminosity per experiment.}
\label{fig:Bs_mixing_projection.eps}
\end{figure}

In the intense international search for the Standard Model Higgs
boson, the Tevatron is anticipated to play a vital role.  With samples
of 4~fb$^{-1}$, potentially attainable before the end of the period of
LHC commissioning, 3$\sigma$ evidence for Higgs masses greater than
the LEP limit (114.4 GeV at 95\% C.L.) will be possible.  With
8~fb$^{-1}$, the 3$\sigma$ evidence could be extended to Higgs masses
as high as 130~GeV.  This mass region, favoured by electroweak data
and supersymmetry, represents a particular challenge to the LHC
experiments, which, to explore it, would need ideal and well
understood detector performance, more than 10~fb$^{-1}$ of data per
experiment, and effective rejection of high backgrounds.  If the SM
Higgs boson were to lie in this favoured region, these challenges, in
addition to the fact that the Tevatron and LHC are sensitive to
different Higgs decay modes, underscore the critical importance of the
development of a multi-fb$^{-1}$ CDF-II physics programme.  The
shortened time-to-discovery that such a complementarity between the
LHC and Tevatron programmes will promote will also serve to inform
urgent planning for the International Linear Collider.

Supersymmetric mass scales could be accessible to the Tevatron if SUSY
is the mechanism for maintaining radiative stability at both the
electroweak and GUT energy scales.  Using the most straightforward
model-independent signature of jets and missing transverse energy, the
mass discovery reach for gluinos and squarks increases by over 20~GeV
for an increase in time-integrated luminosity from 2~fb$^{-1}$ to
8~fb$^{-1}$.  In the case of gaugino-partner (chargino and neutralino)
production with the distinctive decay signature of no jets, three
charged leptons, and missing transverse energy, the gain from
luminosity is even greater: 30~GeV for chargino masses when increasing
from 2~fb$^{-1}$ to 4~fb$^{-1}$, and an additional 30~GeV from
4~fb$^{-1}$ to 8~fb$^{-1}$.  It has been noted that these gains in
reach exceed those that were achievable by the energy increase
throughout the LEP2 program.

Run~II has already been able to exclude part of the light-mass regions
of MSSM Higgs boson predictions.  There exists the exciting prospect,
however, of a discovery by the Tevatron of MSSM Higgs bosons in the
large $\tan\beta$ region.  For $\tan\beta = 60$, the $3\sigma$ reach
is expected to be up to masses of 180~GeV for 1~fb$^{-1}$ and 240~GeV
for 8~fb$^{-1}$.

Profound constraints placed on descriptions of electroweak symmetry
breaking are driven by the experimentally challenging reduction of
measurement uncertainties on the masses of the $W$ boson and top
quark.  As the integrated luminosity increases from 2~fb$^{-1}$ to
4~fb$^{-1}$, for example, the anticipated uncertainties on the masses
are expected to improve by $\sim 20$\%; refer to
Fig.~\ref{fig:top_W_singletop}.  Once direct evidence for a Higgs or
similar mechanism begins to be revealed, these precision measurements
will be key to decisive tests of the theory.

\begin{figure}
\begin{center}
\epsfig{figure=Mtop_total.eps,height=1.50in}
\hskip 0.0in
\epsfig{figure=mw_projection.eps,height=1.50in}
\hskip 0.0in
\epsfig{figure=singleTopProjection.eps,height=1.50in}
\end{center}
\caption{ {\bf [left]} Total uncertainty on $m_{\rm top}$ for CDF in
  the lepton-plus-jets channel alone; the reduction with luminosity is
  driven by the statistical nature of the jet-energy-scale (JES)
  uncertainty.  {\bf [centre]} Extrapolation of the scaling of the
  $m_W$ uncertainty with increasing luminosity.  {\bf [right]}
  Projected sensitivity for single-top production for the $s$ and $t$
  channels combined, not taking into account systematic
  uncertainties.}
\label{fig:top_W_singletop}
\end{figure}

Clearly, some measurements made using the anticipated Tevatron Run~II
data will later be repeated at the LHC with enhanced statistics.  We
note, however, that in some cases the two accelerators probe different
regions of initial-state dynamics, by virtue of the different beam
energies and particles.  In addition to the complementary low-mass
Higgs reaches mentioned above, electroweak single-top production at
the two accelerators is expected to have differing contributions to
the $s$ and $t$ channels, each of which have different sensitivity to
new physics processes.  Single-top production may first be observed
($5\sigma$) at the Tevatron using a time-integrated luminosity of $5 -
7$~fb$^{-1}$; refer to the projection depicted in
Fig.~\ref{fig:top_W_singletop}.  In a similar spirit, and to enhance
the chances of discovering physics beyond the SM, efforts to
understand the relative strengths of different $b\bar{b}$ and
$t\bar{t}$ QCD hadroproduction mechanisms at the Tevatron are needed
for comparison with similar measurements to be made at the LHC, where
markedly different contributions to the same production mechanisms are
anticipated.

% **** Stuff to get section to compile standalone (begin)
%\end{document}
% **** Stuff to get section to compile standalone (end)