%
%  SUSY-Higgs Workshop 2001 - Tevatron Higgs Search 
%
\documentstyle[epsfig,colordvi,tevsearch]{slides}

\input latex.macros
\input top.macros
\def\DZero{D$\mbox{0\kern-.55em /}$}
\def\mDZero{{\rm D}\mbox{0\kern-.55em /}}
\def\mGeVcc{{\rm GeV\, c^2}}
\def\bbbar{$b\bar{b}$}
\def\mbbbar{b\bar{b}}
\def\hsm{H_{SM}}
\def\invcms{${\rm{ cm^{-2} s^{-1}}}$}
\def\reference#1{{\flushright{\hfill \tiny #1}}}
\def\tablespace{\rule{0cm}{.3cm}}
%

\newcommand{\tit}[1] {
        \begin{center}
        \normalsize
        \fbox{\Red{#1}} \vspace{.25in}
        \small
        \end{center}
}


\def\met{\mathbin{E\mkern - 11mu/_T}}

\begin{document}

\small

\tit{Tevatron Higgs Searches in Run II}

\Start
\vspace{0.5in}
\begin{center}
Pekka Sinervo\\
{\it University of Toronto}
\end{center}

\vspace{0.5in}

\Red{Overview}

\tiny
\begin{itemize}
\item Overview of Higgs signatures
\item Higgs Production and Decay
\item Tevatron and CDF/\DZero\ upgrades
\item B Tagging Capabilities and Jet Resolution
\item Sensitivity for a Standard Model Higgs
\item SUSY Higgs detection
\item Summary
\end{itemize}

\tiny

\pagebreak
%
%  Intro to SM 
%
\tit{The Standard Model}

\small
The ingredients of the SM are
\tiny
\begin{itemize}
	\item 12 fermions
	\begin{itemize}
		\item 6 quarks (u, d, s, c, b, t)
		\item 6 leptons	($e^-$, $\nu_e$, $\mu$, $\nu_\mu$,
			$\tau$, $\nu_\tau$)
	\end{itemize}
	\item 3 electroweak bosons ($\W^+$, $W^-$, $Z^\circ$,
			$\gamma$)
	\item 8 gluons to describe the strong force
	\item ?? to describe gravity
\\[0.05in]
\end{itemize}

\small
Enormously successful paradigm since $\sim1975$
\tiny
\begin{itemize}
	\item Predicted rich phenomenology
	\item Accurate! (eg. $\delta_{M_z}/M_z \sim 8\times 10^{-5}$)
	\item Successfully predicted existence of charm and top quark 
\\[0.05in]
\end{itemize}

\small
Higgs boson the only ``essential'' missing element
\tiny
\begin{itemize}
	\item Represents a significant ``vacuum'' of knowledge
	\item Its discovery has the highest scientific urgency
\end{itemize}

\pagebreak
\tit{Brief Overview of Higgs Phenomenology}
%
\small
Higgs allows ``spontaneous symmetry breaking'' in SM
\tiny
\begin{itemize}
	\item Sets the EWK mass scale
	\item Yukawa interactions with fermions generates mass
\\[0.05in]
\end{itemize}

\begin{center}
\centerline{\psfig{file=shw/theory/hunt10a.ps,width=3cm,angle=90}
\hskip1pc \psfig{file=shw/theory/hunt10b.ps,width=3cm,angle=90}
\hskip1pc
\psfig{file=shw/theory/hunt10c.ps,width=3cm,angle=90}}
\vskip1pc
\end{center}

\small
It couples to quarks, leptons and EWK gauge bosons
\tiny
\begin{itemize}
	\item Production rate set by mass \&\ couplings
to ``beam'' 
	\item Decays are mediated by same couplings
	\item In \ppbar\ collisions, produced
	\begin{itemize}
		\item via $q\bar{q}$\ annihilations through
		\begin{itemize}
			\item virtual $W/Z$\ for light quark initial states
			\item directly via $b\bar{b}$\ initial states
		\end{itemize}
		\item indirectly in $gg$\ interactions
		through $gg\rightarrow \mttbar \rightarrow H$
	\end{itemize}
\end{itemize}

\pagebreak
\tit{Current Limits on the Higgs}
\small 
Data point to a low mass Higgs
\tiny
\begin{itemize}
	\item LEP II data excludes $M_H < 113$\ \GeVcc
	\begin{itemize}
		\item suggests an effect around 115 \GeVcc
	\end{itemize}
	\item Tevatron \&\ LEP II data imply $M_H \lessim 200$\
\GeVcc
\end{itemize}

\begin{center}
\epsfysize=3.5in
\epsffile[30 140 520 630]{figures/top_mass/mwmt_cdf_d0_lep2.ps}
\end{center}

\small
The Higgs sector is already constrained
\tiny
\begin{itemize}
	\item LEP II limit of 113 and $\sim200$\ \GeVcc\
	\item A Higgs discovery could be just around the ``corner''
\end{itemize}

\pagebreak
\tit{Features of a Light SM Higgs}
%
\small
Higgs couplings to fermions \&\ EWK bosons specify BR
\tiny
\begin{itemize}
	\item In region $M_H<130$\ \GeVcc, $H\rightarrow \mbbbar$\ dominates
	\item For $M_H>130$\ \GeVcc, $H\rightarrow W W^*$\ takes over
	\item Cross over is $\sim 135$\ \GeVcc
	\item Other decay modes important, but are not relevant to a
Tevatron search
\\[0.10in]
\end{itemize}
\vskip1pc

\centerline{\psfig{file=shw/theory/brsm_new.eps,width=10cm}}

\reference{Dicus, Steltzer, Sullivan \&\ Willenbrock, PRD D59 (1999)
\\  \hfill Spira, private comm.}

\small

\pagebreak
\tit{Higgs Production Cross Section}

\small
Cross section at Tevatron energies miniscule
\tiny
\begin{itemize}
	\item Arises from small couplings to light fermions
	\item Makes ``associated'' production quite important
\end{itemize}

\centerline{\psfig{file=shw/theory/cxnsmnew.ps,width=9cm,angle=-90}}

\small
Some relevant points of reference:
\tiny
\begin{itemize}
	\item Total cross section $\sim 7\times 10^{10}$\ pb
	\item Smallest measured total cross section $\sim 5$\ pb 
	\item Lowest upper limits $\sim 0.1-0.2$~pb ($W^\prime$)
\end{itemize}

\pagebreak
\tit{Tevatron Upgrades for Run II}
%
\small
Tevatron has been significantly improved for Run II 
\tiny
\begin{itemize}
	\item Main Injector replaces Tevatron for injection
	\begin{itemize}
		\item Better $\bar{p}$\ transfer efficiency
		\item Emittance better-matched at injection
	\end{itemize}
	\item Antiproton Recycler -- effective doubling in $\bar{p}$\
production rate
	\item Increase in $\sqrt{s}$\ from 1.8 to 2.0 TeV
	\begin{itemize}
		\item[$\Rightarrow$] 30-40\% increase in production
$\sigma$
	\end{itemize}
	\item Go from $6\times 6 \rightarrow 36\times 36$\ operation
	\begin{itemize}	
		\item Reduces interactions per crossing
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
Performance goals for collider are
\tiny
\begin{itemize}
	\item Increase typical $L_{max}$\ from $1.6\times 10^{31}$\
	to $2\times 10^{32}$~\invcms
	\item Deliver $\sim2$~\invfb\ by 2002 (Run IIa)
	\item If successful in increasing $\bar{p}$\ availability
	\begin{itemize}
		\item Go to $108\times 108$\ operation
		\item Increase $L_{max}$\ to $5\times 10^{32}$~\invcms
		\item Deliver $\sim15$\ \invfb\ by end of 2007 (Run IIb)
	\end{itemize}
\end{itemize}

\pagebreak
\tit{CDF Upgrades for Run II}
%
\small
CDF has undergone major upgrades for Run II
\tiny
\begin{itemize}
	\item Tile-scintillating fibre calorimeters in $1.0<|\eta|<3.6$
	\item Central outer tracker (COT)
	\item SVX II and ISL silicon tracking systems
	\item Fully pipelined electronics and new L1/L2/L3 triggers
	\item Upgraded muon systems in $0.8\le|\eta|\le1.2$
	\item C++ offline reconstruction and new processing farm
\end{itemize}

\centerline{\parbox{5.2in}{\epsfxsize=12cm\epsffile{figures/cdfiso_transp.eps}}}


\pagebreak
\tit{\DZero\ Upgrades for Run II}
%
\small
\DZero\ has undergone a similar transformation
\tiny
\begin{itemize}
	\item New charged particle tracking system
	\begin{itemize}	
		\item 2.0 T solenoid
		\item Inner silicon microstrip tracker (SMT)
		\item New scintillating fibre tracker (CFT)
	\end{itemize}
	\item Preshower detectors to improve $e/\pi$\ separation
	\item Forward muon system chambers \& scintillators
	\item Restructured L1/L2/L3 trigger, electronics and DAQ
\end{itemize}

\pagebreak
\centerline{\parbox{8.0in}{\epsfxsize=\hsize\epsffile{d0_tracker.eps}}}


\pagebreak
\tit{Higgs Detection during Run II}
%
\small
SM Higgs production is in principle detectable
\tiny
\begin{itemize}
	\item Search of Run I data is clear demonstration 
	\begin{itemize}
		\item see G.~Watts' parallel talk
	\end{itemize}
	\item For case of $M_H=120$~\GeVcc, cross section 
	\begin{itemize}
		\item for $gg\rightarrow \hsm$\ is $\sim 0.9$~pb
		\item for $q\bar{q}'\rightarrow W\,\hsm$\ is $\sim 0.2$~pb
		\item for $q\bar{q}\rightarrow Z\,\hsm$\ is $\sim 0.1$~pb
	\end{itemize}
	\item Issues for detection are:
	\begin{itemize}
		\item Reconstruction technique and signal efficiency
		\item Background rejection
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
Run II SUSY/Higgs Workshop has focussed activity
\tiny
\begin{itemize}
	\item Summarizes multiple studies done on 
	\begin{itemize}
		\item SM Higgs production
		\item MSSM Higgs scenarios
	\end{itemize}
	\item Results provided in terms of $\int L dt$
	\item Report from workshop now available (hep-ph/0010338)
\end{itemize}

\pagebreak
\tit{Workshop Tools}
%
\small
Participants explored complementary approaches
\tiny
\begin{enumerate}
	\item Used existing CDF results and extrapolated
	\begin{itemize}
		\item Accounted for SVX improvements
		\item Took into account new triggers
		\item Extrapolated jet resolution improvements
	\end{itemize}
	\item Developed independent detector simulation (``SHW'')
	\begin{itemize}
		\item Parametrized resolutions and acceptances
		\item Took account of \DZero\ and CDF upgrades
		\begin{itemize}
			\item Provide model of ``average'' detector
		\end{itemize}
	\end{itemize}
	\item Assessed neural-net and ``advanced'' analysis techniques
\\[0.05in]
\end{enumerate}

\small
Results provided for many scenarios and channels
\tiny
\begin{itemize}
	\item Resulted in a fairly coherent set of predictions
	\begin{itemize}
		\item Assessed impact of ``combined'' statistical power
		\item Also noted some areas where uncertainties remain
		large
	\end{itemize}
	\item Signal-to-noise issues are key to success
\end{itemize}

\pagebreak
\tit{B Tagging Issues}
%
\small
``B Tagging'' an amalgam of various techniques
\tiny
\begin{itemize}
	\item Secondary vertex tagging primary technique (SECVTX)
	\begin{itemize}
		\item Identify tracks with large impact parameter 
		\item Search for 2 or 3-track combinations with large $L_{xy}$
	\end{itemize}
% \begin{center}
\parbox{2.0in}{\epsfxsize=5in\epsffile{shw/btag/perigee-sec2.eps}}
% \end{center}
	\item Probability of tracks coming from primary vertex (JPB tag)
	\item Identify soft leptons in core of b-jet (SLT)
\end{itemize}

\pagebreak
\tit{Tight and Loose B Tags}
%
\small
Employ concept of a ``tight'' and ``loose'' tag
\tiny
\begin{itemize}
	\item Tight $\Rightarrow$ SECVTX tag
	\item Loose $\Rightarrow$ Either SECVTX, JPB or SLT
	\item Allows trade-off between efficiency \&\ bkg rejection
\\[0.05in]
\end{itemize}

\small
Use CDF Run I tagging efficiency 
\tiny
\begin{itemize}
	\item Account for increase in SVX acceptance
	\item Use Run I mistag rates
\\[0.05in]
\end{itemize}

  \begin{center}
    \parbox{3.0in}{\epsfxsize=\hsize\epsffile{shw/shw/b-tag-lin.eps}}
    \parbox{3.0in}{\epsfxsize=\hsize\epsffile{shw/shw/b-tag-log.eps}}
  \end{center}

\pagebreak
\tit{Higgs Mass Resolution}
%
\small
Higgs mass resolution relies on jet reconstruction
\tiny
\begin{itemize}
	\item ``Standard'' CDF jet algorithm 
	\begin{itemize}
		\item gives $M_H$\  resolution $\sim 16$\
\GeVcc\ at $M_H=110$\ \GeVcc
	\end{itemize}
	\item Track \&\ shower-max data provides $\sim 20-30$\%\ improvement
	\begin{itemize}
		\item Measured using photon-jet balancing
\\[0.01in]

	\end{itemize}
  \begin{center}\hbox{
  \parbox{3.25in}{\epsfxsize=\hsize\epsffile{shw/bbmass/jetscale.eps}}
  \parbox{3.25in}{\epsfxsize=\hsize\epsffile{shw/bbmass/escale.eps}}}
  \end{center}
\end{itemize}

\pagebreak
\tit{Assumed Improvement in Mass Resolution}
\small
Provides $10-20$\%\ improvement in $H\rightarrow\mbbbar$\
mass 
\begin{center}
\parbox{3.0in}{\epsfxsize=\hsize\epsffile{shw/bbmass/zbb_corr_pyt_mass_evol.eps}}
\parbox{3.0in}{\epsfxsize=\hsize\epsffile{shw/bbmass/zbb_corr_her_h_evol.eps}}
\end{center}

\small
This still requires work
\tiny
\begin{itemize}
	\item Topology dependence needs to be understood
	\begin{itemize}
		\item Overlap with other objects in event
		\item Combinatorial confusion
	\end{itemize}
	\item Take into account other calorimetry effects
	\item Overall, promising development for Run II
\end{itemize}
\pagebreak
\tit{Detection Strategy for Light SM Higgs}
%
\small
The most promising channels for a light SM Higgs are
\tiny
\begin{eqnarray}
	\mppbar &\rightarrow& W^+\, H \rightarrow l^+ \nu_l \ \mbbbar 
\nonumber \\
	\mppbar &\rightarrow& Z^0\, H \rightarrow l^+ l^- \ \mbbbar 
\nonumber
\end{eqnarray}
\begin{itemize}
	\item Identify $e^+$\ or $\mu^+$\ with $p_T > 20$\ \GeVc
	\item Require \MEt$>20$\ GeV and reject dilepton events
	\item Only two jets with $E_T>25$\ GeV and $>10$\ GeV with
$|\eta|<2$
	\begin{itemize}
		\item Both b-tagged (one tight and one loose)
		\item Impose $M_{bb}$\ mass window $\sim \pm15$\%
		\item No extra jets with $E_T>20$\ GeV and $|\eta|<2.4$
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
Results in $\epsilon\times{\cal B}(H\rightarrow \mbbbar) \sim2$\%\ 
\tiny
\begin{itemize}
	\item Expected 8 fb observed for $M_H=90$\ \GeVcc
	\begin{itemize}
		\item Falls to 2 fb for $M_H=130$\ \GeVcc
	\end{itemize}
\end{itemize}


\pagebreak
\tit{Background Rates for $WH$}
%
\small
All of the above come down to control of backgrounds
\tiny
\begin{itemize}
	\item Non-physical backgrounds estimated to be small 
	\item Largest physical backgrounds are
	\begin{itemize}
		\item QCD production of $W\, \mbbbar$
		\item Production of \ttbar\ where two jets are missed
		\item Di-vector boson production
		\item Single top production ($tb$\ and $tqb$)
	\end{itemize}
	\item  Use HERWIG and PYTHIA, checked against Run I data
\end{itemize}

\begin{center}
Observed Cross Section (fb) 
\vskip1pc

\begin{tabular}{lccc}
Process     &   $M_H=90$    &  $M_H=110$   &  $M_H=130$  \\
\hline 
\tablespace
Signal      &     8.4       &     5.0      &     2.2     \\
$W\mbbbar$  &    21.5       &    18.9      &    15.4     \\
\ttbar      &     9.6       &    12.2      &    13.0     \\
$VV$        &     7.7       &     4.9      &     0.6     \\
$tb$\ and $tqb$ & 9.4       &    11.8      &    12.7     \\
\hline
\end{tabular}
\end{center}

\pagebreak
\tit{Uncertainties in Signals and Backgrounds}
%
%	Show table of estimates
%	Discuss uncertainties
%
\small
Signal estimates suffer mostly from
\tiny
\begin{itemize}
	\item Uncertainties on b-tagging estimates
	\item Jet resolution estimates
	\item Uncertainties in production rates
	\item How large?  SHW estimates are about 10-20\% higher
\\[0.05in]
\end{itemize}

\small
What should you worry most about backgrounds?
\tiny
\begin{itemize}
	\item Rate of $W\mbbbar$\ remains uncertain 
	\begin{itemize}
		\item Other physical backgrounds reasonably well understood
	\end{itemize}
	\item Could $W\mbbbar$\ be $\times 2$\ larger?
	\begin{itemize}
		\item Probably not...CDF estimate constrained by
		the b-tagging rates and kinematic data
		\item Also have other tools not used
		\begin{itemize}
			\item NN approach gets 50\%\ lower background
		\end{itemize}
	\end{itemize}
	\item Remains a challenge in this analysis
\end{itemize}

\pagebreak
\tit{Results for $ZH$\ Channel}
%
%  Note difference in efficiency
%	ll bbbar channel rather clean
%	nu nu bbbar channel difficult
\small
$ZH \rightarrow l^+l^-\, \mbbbar$\ is straightforward
\tiny
\begin{itemize}
	\item Suffer about $\times 5$\ hit due to BR and
lepton ID efficiency
	\item Expect about 1/6 of $WH$\ observed rate
	\item Background rates are also approximately 1/6-1/7
\\[0.05in]
\end{itemize}

\small
$ZH \rightarrow \nu_l\bar{\nu}_l\, \mbbbar$\ presents challenge
\tiny
\begin{itemize}
	\item Only have \MEt\ signature from $Z\rightarrow \nu\bar{\nu}$
	\item Have two b-tagged jets reconstructing to $H$
	\item Creates a very ``modest'' signature
	\begin{itemize}
		\item Issues with triggering
		\item Issues with beating down the backgrounds
	\end{itemize}
\end{itemize}

\pagebreak
\tit{Backgrounds to $\nu\bar{\nu}\, \mbbbar$\ Final State}
%
\small
Physical backgrounds reasonably well understood 
\tiny
\begin{itemize}
	\item QCD production of $Z\mbbbar$
	\item QCD production of $W\mbbbar$\ (miss charged lepton)
	\item $WZ$\ and $ZZ$
	\item \ttbar\ and single top
\\[0.05in]
\end{itemize}
\tiny
\begin{center}
Observed cross section (fb) \\
\vskip0.1in

\begin{tabular}{lccc}
Process     &   $M_H=90$    &  $M_H=110$   &  $M_H=130$  \\
\hline 
\tablespace
Signal      &     3.6       &     2.7      &     0.9     \\
$Z\mbbbar$  &     6.5       &     4.9      &     3.8     \\
$ZZ$        &     5.4       &     3.4      &     0.0     \\
\ttbar      &     1.6       &     2.2      &     2.2     \\
\hline \\[0.01in]
$q\bar{q} \rightarrow \mbbbar$
            &     $\sim7$   &     $\sim6$  &  $\sim 3$   \\
\hline
\end{tabular}
\end{center}

\vskip.1in
\small
QCD $\mbbbar$\ background difficult to estimate
\tiny
\begin{itemize}
	\item Depends crucially on \MEt\  measurement
	\item Raw production cross section not well understood
	\item[$\Rightarrow$] Have to measure with data
\end{itemize}

\pagebreak
\tit{Higher Mass Higgs Searches}
%
\small
Heavier Higgs ($M_H\gessim 130$\ \GeVcc) rates lower
\tiny
\begin{itemize}
	\item $H \rightarrow WW^*$\ becomes dominant decay mode
	\item Production via $gg\rightarrow HX$\ and $q\bar{q}'
\rightarrow WH$\ are important
	\item Realistically, will require in excess of 15 \invfb
\end{itemize}

\begin{center}
\parbox{5.5in}{\epsfxsize=\hsize\epsffile{shw/highmass/sigxbr.eps}}
\end{center}

\small
This presents a number of decay channels
\tiny
\begin{eqnarray}
\mppbar &\rightarrow& H \rightarrow W^*W^* \rightarrow l\bar{l}\nu_l
\bar{\nu}_l 
\nonumber \\
\mppbar &\rightarrow& W^+H \rightarrow W^+W^*W^* \rightarrow l^+l^+
q\bar{q}' X
\nonumber 
\end{eqnarray}
\begin{itemize}
	\item These two represent the highest rate topologies
	\item Same-sign dileptons very clean
\end{itemize}


\pagebreak
\tit{Signal and Background Estimates}
%
\small
Signal requirements for $H\rightarrow l\bar{l}'\nu_l \bar{\nu}_l$\ are:
\tiny
\begin{itemize}
	\item Isolated leptons with $p_T>10$\ \GeVc\ and $|\eta|<1.5$
	\item Require $M_{ll'}<78$\ \GeVcc\ for $e^+e^-$\ and $\mu^+\mu^-$
	\begin{itemize}
		\item and $M_{ll'}<110$\ \GeVcc\ for $e^+\mu^-$
	\end{itemize}
	\item Make decay angle cuts to reject $\tau^+\tau^-$\ events
	\item Reject events with high energy jets (eg., $E_T>95$)
\\[0.05in]
\end{itemize}

\small
A more sophisticated likelihood analysis defines
\begin{eqnarray}
M_C \equiv \sqrt{p_T^2(ll) + M^2(ll)} + \mMEt \nonumber
\end{eqnarray}
\begin{center}
\parbox{6.0in}{\epsfxsize=\hsize\epsffile[0 260 530 530]{shw/highmass/m170_paper.eps}}
\end{center}

\pagebreak
\tit{Heavy Higgs Signal and Background Rates}
%
\small
Estimates of signal and background rates 
\tiny
\begin{itemize}
	\item Dominated by $W^+W^-$\ and \ttbar
\\[0.05in]
\end{itemize}
\tiny

\begin{center}
Observed Cross Section (fb) \\
\vskip.1in
\begin{tabular}{lccc}
Process     &   $M_H=140$    &  $M_H=160$   &  $M_H=180$  \\
\hline 
\tablespace
Signal      &     2.6       &     1.5      &     1.0     \\
Backgrounds &     4.4        &     4.4      &     3.8     \\
$S/\sqrt{B}$&     2.1       &     3.9      &     2.7     \\
\hline
\end{tabular}
\end{center}
\vskip.1in


\small
Can estimate total integrated luminosity needed
\tiny
\begin{itemize}
	\item For either $3\sigma$\ observation or 95\%\ CL exclusion
	\item Include 10\%\ systematic uncertainty
\end{itemize}


\begin{center}
\parbox{6.0in}{\epsfxsize=\hsize
\epsffile[0 260 530 530]{shw/highmass/contour_gg_paper.eps}}
\end{center}


\pagebreak
\tit{Associated Production of $\mttbar H$}
\small
Recently, $\mttbar H$\ has been reexamined at the Tevatron

\tiny
\reference{Goldstein et al, hep-ph/0006311}

\tiny
\begin{itemize}
	\item Analogous to $\mbbbar H$\ channel
	\item The \ttbar\ gives efficient trigger and tag
\\[0.1in]
\end{itemize}

\small
Signal cross  sections are small
\tiny
\begin{itemize}
	\item Estimate $\sigma\times{\cal B}$\ of $\mttbar H$\ few fb
\end{itemize}

\begin{picture}(0,0)(0,0)
\special{psfile=ttbarH/crossec.eps
         voffset=-220 hoffset=10 hscale=35 vscale=40 angle=0}
\special{psfile=ttbarH/signal.ps
         voffset=-248 hoffset=650 hscale=75 vscale=75 angle=90}
\end{picture}
\vspace{7.5cm}
% \begin{center}
% \parbox{4.5in}{\epsfxsize=\hsize\epsffile{ttbarH/signal_new.eps}}
% \end{center}

\pagebreak
\tit{$\mttbar H$\ Rates}
\small
Have to deal with very large $\mttbar X$\ background
\tiny
\begin{itemize}
	\item $\mttbar + jj$\ has rate of $\sim 1,000$\ fb
	\item B-tagging is crucial to pull out signal
	\begin{itemize}
		\item Require 2 jets, at least one b-tagged 
	\end{itemize}
	\item For $M_H=120$\ \GeVcc\ and 15~\invfb
	\begin{itemize}
		\item 2-3 signal events and little background
\\[0.1in]
	\end{itemize}
\end{itemize}
\small
Could yield a few ``spectacular'' events
\vskip1pc

\begin{center}
\parbox{4.0in}{\epsfxsize=\hsize\epsffile{ttbarH/prl_rev_001011_ji.eps}}
\end{center}

\pagebreak
\tit{Summary for SM Higgs Search}
\small
Results of the Workshop analysis can be combined:
\tiny
\begin{itemize}
	\item Use results of NN analysis
	\item Combine statistical power of both experiments
	\item Bands reflect 30\%\ total additional ``shift''
\end{itemize}
  \begin{center}
    \parbox{6.0in}{\epsfxsize=\hsize\epsffile[0 200 500 540]
           {shw/combine/final.ps}}
  \end{center}


\pagebreak
\tit{MSSM Higgs Search}
\small
Search for MSSM Higgs has to grapple with
\tiny
\begin{itemize}
	\item 5 Higgs bosons in minimal model
	\begin{itemize}
		\item two $CP$-even scalars $h$\ and $H$
		\item CP-odd scalar $A$
		\item pair of charged states $H^\pm$
	\end{itemize}
	\item A larger number of parameters
	\begin{itemize}
		\item $\tan\beta = v_1/v_2$\ and $M_A$
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
Sketch ``benchmark'' measure of Tevatron sensitivity
\tiny
\begin{itemize}
	\item Look at two production models
	\begin{itemize}
		\item $q\bar{q} \rightarrow V \phi \rightarrow V \mbbbar$
		\item $gg$\ or $q\bar{q} \rightarrow \mbbbar \phi \rightarrow 
				\mbbbar\, \mbbbar$
	\end{itemize}
	\item Reinterpret limits from earlier analyses
\begin{eqnarray}
R_{th}(X,Y) &=& {{\sigma_X(\phi)\, {\cal B} (\phi\rightarrow Y)}\over{
  	     \sigma_X(h_{SM})\, {\cal B} (h_{SM} \rightarrow Y)}}
\nonumber
\end{eqnarray}

\end{itemize}

\pagebreak
\tit{Reinterpreting SM Search Results}
\small
Take results from SM $WH \rightarrow W \mbbbar$\ and 
$ZH \rightarrow Z \mbbbar$\ 
\tiny
\begin{itemize}
	\item Determine range of 95\%\ exclusion and $5\sigma$\
sensitivity
	\item Add 10\%\ systematic uncertainty
\end{itemize}

\centerline{\psfig{file=shw/mssm/rvalues95_2000.eps,width=9cm,angle=0}
\hfill
\psfig{file=shw/mssm/rvalues5_2000.eps,width=9cm,angle=0}}

\begin{eqnarray}
R_{\rm th}(q\bar q'\to V\phi\,;\,b\bar b)\equiv
\left({g^2_{VV\phi} \over g^2_{VV\hsm}}\right)
\left[{{\rm BR}(\phi\to b\bar b)\over {\rm BR}(\hsm\to b\bar
b)}\right]
\nonumber
\end{eqnarray}

\vskip0.1in

\small
Can map these limits onto specific MSSM models 

\pagebreak
\tit{Looking at non-SM Channels}
\small
Final states  that are unique to the MSSM Higgs
\tiny
\begin{itemize}
	\item SM production or decay rate is suppressed
	\item Results in a observable signature at Tevatron
	\item ``Benchmark'' example (for large $\tan\beta$) is
\end{itemize}
\begin{eqnarray}
gg\ {\rm or}\ q\bar{q} \rightarrow \mbbbar \phi \rightarrow 
		\mbbbar\, \mbbbar
\nonumber
\end{eqnarray}

\small
Search for $\mbbbar\, \mbbbar$\ final states:
\tiny
\begin{itemize}
	\item Require 4 jets, $E_T>15$\ GeV and $|\eta|<2.1$
	\item 1st and 2nd jet $E_T > 40-75$\ GeV ($M_H = 70-200$\
\GeVcc)
	\item Require 3 $b$-tagged jets
	\item Reconstruct $\phi \rightarrow \mbbbar$\ signal
\end{itemize}

\pagebreak
\tit{Higgs Reconstruction \bbbar\ Mode}
\small
Use a mass-dependent strategy to reconstruct $H$
\tiny
\begin{itemize}
	\item highest-$E_T$\ pair of jets for $M_H>120$\ \GeVcc
	\item 2nd and 3rd highest-$E_T$\ jets for $M_H\le 120$\ \GeVcc
\end{itemize}

\centerline{\parbox{5.2in}{\epsfxsize=\hsize\epsffile{shw/bbbb/sigres.eps}}}

\pagebreak
\tit{Estimated Signal and Background}
\small
Signal efficiency is relatively small
\tiny
\begin{itemize}
	\item Ranges from 0.4\%\ to 0.5\%\
	\item Dominated by trigger requirements and $b$-tagging
\\[0.05in]
\end{itemize}

\small
Backgrounds are large (and somewhat uncertain)
\tiny
\begin{itemize}
	\item QCD background dominates (and largely irreducible)
	\item \ttbar\ is next largest (about 1/5 of QCD)
\end{itemize}

\tiny

\begin{center}
Observed Cross Section (fb)  \\
\vskip.1in

\begin{tabular}{lccc}
Process     &   $M_H=120$    &  $M_H=140$   &  $M_H=200$  \\
\hline 
\tablespace
Signal      &     19       &     10       &     1.1     \\
QCD	    &    $55\pm12$  &  $34\pm9$  &    $9\pm3$  \\
\ttbar      &    $13\pm3$   &  $11\pm3$  &   $4\pm 1$  \\
$S/\sqrt{B}$&     2.2       &     1.4      &     0.3     \\
\hline
\end{tabular}
\end{center}


\pagebreak
\tit{Summary of MSSM Higgs Mass Sensitivity}
\small
Can summarize these data
\tiny
\begin{itemize}
	\item 95\%\ CL upper limits on $\tan\beta$\ vs $M_H$
	\item Estimate $3\sigma$\ and $5\sigma$\ contours
\end{itemize}

\centerline{\parbox{4.8in}{\epsfxsize=\hsize\epsffile{shw/bbbb/run2tanb.eps}}
}

\small
Has extended reach for very large $\tan\beta$\ values
\tiny
\begin{itemize}
	\item Large uncertainties in the QCD background
	\item $b$-tagging backgrounds are in ``virgin'' territory
\end{itemize}

\pagebreak
\tit{Summary}
\small
Higgs search at the Tevatron shows clear promise
\tiny
\begin{itemize}
	\item Limited reach with 2~\invfb\ (2002 goal)
	\item Data set of 15-20~\invfb\ does have sensitivity
	\begin{itemize}
		\item Could discover SM Higgs up to 115-125 \GeVcc
		\item Sensitive to MSSM models over large parameter space
	\end{itemize}
\end{itemize}

\small
``Gold-plated'' modes are
\tiny
\begin{itemize}
	\item $\mppbar \rightarrow VH \rightarrow V \mbbbar$\ for
$M_H\lessim 130$\ \GeVcc
	\item $\mppbar \rightarrow H \rightarrow V V^*$\ for
$M_H\gessim 130$\ \GeVcc
\end{itemize}

\small
Many uncertainties in these predictions
\tiny
\begin{itemize}
	\item Based on Run I flavour-tagging experience
	\item Requires optimal kinematic reconstruction tools
	\begin{itemize}
		\item Promising results on dijet mass reconstruction
		\item Have to be reproduced in Run II environment
		\item Resolution in \MEt\ critical in some modes
	\end{itemize}
	\item Will have to be resolved with the data
\end{itemize}

\end{document}
