%
%  Top talk for WRNPPC - Feb 2000
%
\documentstyle[epsfig,colordvi,wrnppc]{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}}
%

\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{What We Know About Truth}

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

\vspace{0.5in}

\Red{Overview}

\tiny
\begin{itemize}
\item Standard Model Framework for Top
\item Theoretical Leverage from Top
\item Review of Run I Top Physics
\begin{itemize}
	\item Top Quark Mass
	\item Production and Decay Rates
	\item Kinematics
	\item Single Top
\end{itemize}
\item Prognostications
\end{itemize}

\tiny
\begin{flushright}
Work done in collaboration with Pierre Savard \\
and Andrew Robinson
\end{flushright}

\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. $\delta_{M_z}/M_z \sim 8\times 10^{-5}$)
\\[0.05in]
\end{itemize}

\small
It predicted existence of top quark almost 20 years ago

\pagebreak
\tit{Why a Top Quark?}

In 1977, Lederman et al. reported a new resonance
\tiny
\begin{itemize}
	\item Mass of $9.54\pm0.04$~\GeVcc
	\item Decayed to $\mu^+\mu^-$\ pairs
	\item[$\Rightarrow$] A fifth quark
	\begin{itemize}
		\item Production rate $\Rightarrow$\ $Q=-1/3$
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
Studies established that it should have a partner
\tiny
\begin{itemize}
	\item Certain types of decays didn't occur
	\begin{itemize}
		\item decays like $b\rightarrow \mu^+\mu^- d$\ not observed
	\end{itemize}
	\item $e^+e^-\rightarrow b\bar{b}$\ scattering suggested
	an $SU(2)$\ state
\end{itemize}

\pagebreak
\tit{The Top Quark Mass in the Standard Model}
\small
The SM ``needs'' a massive top quark
\tiny
\begin{itemize}
	\item Loop effects in SM driven by $M_{top}$
	\begin{itemize}
		\item $W/Z$\ boson mass ratio
		\item $b-\bar{b}$\ mixing
	\end{itemize}
\end{itemize}
\vspace{0.3in}
\vbox{
\vskip+0.0in
\hskip+3.0in
\special{psfile=physics_figures/mass_loops.eps  hscale= 50.0 vscale= 50.0}
\vskip-0.2in
}
\vspace{1.8in}
\vbox{
\vskip+0.0in
\hskip+0.0in
\special{psfile=figures/physics_figures/b_bbar_mixing.eps  hscale= 80.0 vscale= 80.0}
\vskip-0.0in
}

\small
However, no real information on $M_{top}$
\tiny
\begin{itemize}
	\item In 1983, knew it had to be large ($\gessim 20$~\GeVcc)
	\item Searches limited by collider centre-of-mass energies
\end{itemize}
\pagebreak

%
\tit{SM Top Quark Phenomenology} 

\small
Top quarks decay via the weak force
\tiny
\begin{itemize}
	\item Predict $\sim100$\% $t\rightarrow W^+ b$
	\item For heavy top ($M_{top}\gessim 100-120$ \GeVcc), decays
	before it hadronises \\[0.1in]
\end{itemize}

\small
Can be viewed as ``pure'' $\beta$\ decay
\tiny
\begin{eqnarray}
\Gamma_{\rm top} &=& {{G_F M_t^3}\over{8\sqrt{2} \pi}} 
   \left( 1 - {{M_W^2}\over{M_t^2}} \right)^2 
   \left( 1 + 2{{M_W^2}\over{M_t^2}} \right) \nonumber \\
&\sim& 175\ {\rm MeV}\ \left( {{M_t}\over{M_W}} \right)^3\ \sim\ 2\
{\rm GeV} \nonumber
\end{eqnarray}
\begin{itemize}
	\item Toponium doesn't have time to form
	\item $T$~mesons $\sim$\ degenerate (if there was time...)
\\[0.1in]
\end{itemize}

\small
Decay dominated by ``longitudinal $W^+$''
\tiny
\begin{itemize}
	\item Means the $W^+$\ prefers helicity 0
	\item Result of large top and $W^+$\ mass
\end{itemize}	

\pagebreak

\tit{The Hunt for the Top Quark}

\small
SM didn't tell us the top quark mass
\tiny
\begin{itemize}
	\item Search for evidence in $e^+e^-$\ and $p\bar{p}$\
	\begin{itemize}
		\item Rate decreases sharply with $M_{top}$
		\item By 1989, had set limit of $M_{top}>77$\ \GeVcc
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
By 1992, had new measurements of $M_Z$\ and $M_W$
\tiny
\begin{itemize}
	\item SM predicted top quark with $M_{top} \gessim 140$~\GeVcc
	\item Only place to look was in high-energy $p\bar{p}$\ collisions
	\item Two experiments
	\begin{itemize}
		\item Collider Detector at Fermilab (CDF)
		\item \DZero
	\end{itemize}
\end{itemize}
\pagebreak

%
%  Its there
%
\tit{Discovery of Top}

\small
Hints of top production appeared as early as 1993
\tiny
\begin{itemize}
	\item CDF published a 61 page PRD in Sep 1994
	\item Gave ``cagey'' label to the reports
	\begin{itemize}
		\item ``Evidence for top quark production...''
	\end{itemize}
	\item \DZero's analysis not as definitive
\\[0.05in]
\end{itemize}

\small
With a factor of two more data, result was unequivocal
\tiny
\begin{itemize}
	\item April 1995, both collaborations announced discovery
	\item Confirmed SM predictions -- $M_{top} \sim
			170-190$~\GeVcc
	\item Gave us a ``free quark'' system to study
	\begin{itemize}
		\item[\Blue{$\Rightarrow$}] \Blue{New frontier in 
		particle physics}
	\end{itemize}
\end{itemize}
\pagebreak
%
%  Techniques
%
\tit{Reconstructing Top}

\small
Since top is pair-produced and $\beta$\ decays
\tiny
\begin{itemize}
	\item Expect to see 6 final state particles
\end{itemize}
\vspace{2.0in}
\vbox{
\vskip+7.8in
\hskip-2.0in
\special{psfile=figures/prd_plots/feynman_top_decay.ps  hscale=100.0
vscale=100.0}
\vskip-7.8in
}
\small
Life is normally not that easy -- in reality:

\begin{center}
\epsfysize=3.5in
\epsffile{physics_figures/ttbar_lepton_jets.eps}
\end{center}
\pagebreak
%
% Selecting top decays
%
\tit{Identifying Top Decays in $p\bar{p}$\ Collisions}

\small
In order to identify top candidates
\tiny
\begin{itemize}
	\item Search for $W\rightarrow l \nu_l$\ candidate
	\begin{itemize}
		\item Electron or muon with $P_T>20$~\GeVc
		\item Missing transverse energy $\mMEt>20$~GeV
	\end{itemize}
	\item Search for at least one $b$~jet
	\begin{itemize}
		\item Most effective tool is to find a secondary
		vertex
	\end{itemize}
	\item Some evidence of other $W$\ in event
	\begin{itemize}
		\item Either two more jets or another lepton
	\end{itemize}
\end{itemize}

\vbox{
\vskip+3.3in
\hskip+1.3in
\special{psfile=figures/run1b_blessed_plots/dil_57621_45230_tracking_only.eps
hscale= 90.0 vscale= 90.0}
\vskip 0.5in
}
\pagebreak

%
%  Some history
%
\tit{Status of Collider Experiments}

\small
CDF and \DZero\ collected $\sim110$~\invpb\ of data in 92-96
\tiny
\begin{itemize}
	\item 1.8 TeV $p\bar{p}$\ collisions
	\item Collected events with
	\begin{itemize}
		\item High $P_T$\ leptons ($P_T\gessim10$~\GeVc)
		\item $\MEt>25$~GeV
		\item High $P_T$\ jets ($P_T\gessim100$~\GeVc)
\\[0.05in]
	\end{itemize}
\end{itemize}

\small
Studies have strengthened top quark interpretation
\tiny
\begin{itemize}
	\item Different techniques used to look at the same data
	\begin{itemize}
		\item Kinematic distributions
		\item Neural network approaches
	\end{itemize}
	\item Verified that all decay modes appear to be OK
	\begin{itemize}
		\item See reasonable signals in $\tau$\ lepton final
states
		\item All hadronic modes are also understood
	\end{itemize}
\end{itemize}

\pagebreak
%
%  What do we have now
%
\tit{The Status of Top Today}

\small
CDF has now detected top in virtually all decay modes
\tiny
\begin{itemize}
	\item Lepton + Jets mode (for mass analysis)
	\begin{itemize}
		\item lepton $P_T>20$~\GeVc\ and $\mMEt>20$~GeV
		\item $\ge3$\ jets, $E_T>15$~GeV and $|\eta|<2$
		\item Require 1 $b$-tagged jet OR a 4th jet
		with $E_T>15$
		\item[\Blue{$\Rightarrow$}] \Blue{76 candidates}\
		(expect $31\pm7$\ bkg) \\[0.05in]
	\end{itemize}
%
	\item Dileptons
	\begin{itemize}
		\item 2 leptons with $P_T>20$~\GeVc
		\item Remove Drell-Yan and $Z^\circ$\ background
		\item[\Blue{$\Rightarrow$}] \Blue{9 candidates} 
		($2.4\pm0.5$\ events bkg) 
\\[0.05in]
	\end{itemize}

	\item All hadronic decays
	\begin{itemize}
		\item between 5 and 8 jets ($E_T > 15$~GeV and
		$|\eta|<2.0$)
		\item $\sum E_T > 300$\ GeV + additional kinematic
cuts
		\item[\Blue{$\Rightarrow$}] \Blue{Observe 187 $b$-tagged jets}
		($142\pm11$\ expected bkg)
	\end{itemize}

\end{itemize}

\pagebreak
%
%  What are the Interesting properties
%
\tit{What are the Interesting Top Properties?}

\tiny
\begin{itemize}
	\item Top Quark Mass
	\begin{itemize}
		\item SM constrains it to $M_W/M_Z$ 
		\item Important consistency check of theory
			\\[0.05in]
	\end{itemize}
	\item Top Quark Production Cross Section
	\begin{itemize}
		\item Predicted by QCD with less uncertainties than 
		$\sigma_b$
		\item Look for single top production 
			\\[0.05in]
	\end{itemize}
	\item Top Quark Decay Rates
	\begin{itemize}
		\item Measured $t\rightarrow W^+ b/
			t\rightarrow W^+ q$
		\item Look for $t\rightarrow H^+ b$
			\\[0.05in]
	\end{itemize}
	\item Top Quark Decay Kinematics
	\begin{itemize}
		\item SM expects decay to be polarized
		\item Have made first measurement of polarization
			\\[0.05in]
	\end{itemize}
	\item Single Top Production 
\end{itemize}

\pagebreak

%
%  Top Mass result
%
\tit{Top Quark Mass}

\small
Measurements now limited by statistical uncertainties
\tiny
\begin{itemize}
	\item Overall systematic uncertainty is $\sim 5$~\GeVcc
	\begin{itemize}
		\item Dominated by uncertainties in soft gluon 
		contributions and energy scale
	\end{itemize}
	\item Run I statistics limit systematic uncertainty 
\\[0.05in]
\end{itemize}

\begin{center}
\epsfysize=3.6in
\epsffile[30 140 520 630]{ljm_likfit1.ps}
\end{center}

\small
The final Run I values are 
\tiny
\begin{eqnarray}
	M_{top} &=& 176.0 \pm 6.5 \ \mGeVcc\ {\rm (CDF)} \nonumber \\
	M_{top} &=& 172.1 \pm 7.1 \ \mGeVcc\ {\rm (\mDZero)} \nonumber \\
	M_{top} &=& 174.3 \pm 5.1 \ \mGeVcc\ {\rm (Run I)} \nonumber
\end{eqnarray}

\pagebreak

\small
Latest $W$\ boson mass results
\tiny
\begin{eqnarray}
	M_W &=& 80.433\pm0.079\ \mGeVcc\ \ \ {\rm CDF} \nonumber \\
	M_W &=& 80.474\pm0.093\ \mGeVcc\ \ \  {\rm D0} \nonumber \\
	M_W &=& 80.350\pm0.056\ \mGeVcc\ \ \  {\rm LEP2} \nonumber
\end{eqnarray}

\vspace{.1in}
\begin{center}
\epsfysize=5.5in
\epsffile[30 140 520 630]{mwmt_tevatron_lep2.eps}
\end{center}

\pagebreak

%
%  Top Cross Section
%
\tit{Top Quark Production Cross Section}

\small
The cross section obtained by a fit to 
\tiny
\begin{itemize}
	\item Lepton + jets, dileptons and all hadronic event rates
	\item Depends on $M_{top}$\ because of acceptance
	\item Recent improvement is more accurate $b$-tagging
efficiency
\end{itemize}

\small
\begin{eqnarray}
\sigma_{\mttbar} &=& 6.5^{+1.7}_{-1.4}\ {\rm pb} \nonumber
\end{eqnarray}

\begin{center}
\epsfysize=3.5in
\epsffile[30 140 520 630]{top_xs_cdf_d0.eps}
\end{center}

\tiny
\begin{itemize}
	\item Theory predictions range from 4.7 to 5.5 pb
\end{itemize}

\pagebreak
\tit{Comparison with \DZero}

Measurements by \DZero\ also quite consistent \\[0.5in]

\begin{center}
\epsfysize=5.5in
\epsffile[30 140 520 630]{top_xs_table_new.eps}
\end{center}

\pagebreak

%
%  Top Quark Pt Distribution
%
\tit{Top Quark Transverse Momentum}

\small
SM predicts top quarks produced ``back-to-back''
\tiny
\begin{itemize}
	\item Broad $P_T$\ distribution -- $<P_T> \sim M_{top}/2$
	\item Non-SM predictions can be quite different
	\begin{itemize}
		\item Can test models (such as Top colour or ADD) 
\\[0.05in]
	\end{itemize}
\end{itemize}

\begin{center}
\epsfig{file=hill.eps}
\end{center}          

\small
Limited statistics and experimental resolution present challenge
\tiny
\begin{itemize}
	\item Produce a set of confidence limits on 
${{d\sigma_t}\over{dP_T}}$
	\item Limited to large bins ($\Delta P_T = 75$~\GeVc)
\end{itemize}

\pagebreak

%
%  Event selection for Top Pt Measurement
%
\tit{Event Selection}

\vspace{0.25in}

\small
Use the ``standard'' lepton + jets event selection:
\tiny
\begin{itemize}
	\item Single isolated $e(\mu)$ having $P_T>20$~\GeVc\ and $|\eta|<1.0$
	\item $\met > 20$~GeV
	\item $\ge 4$~jets, 3 with $E_T>15$~GeV and $|\eta|<2.0$
	\begin{itemize}
		\item fourth with $E_T>8$~GeV, $|\eta|<2.4$
	\end{itemize}
	\item To increase signal significance, require that 
\tiny
\begin{center}
$N_{\mathrm{jet15}} \ge 4$ the \Red{or} $N_{tag} \ge 1$
\end{center} 
\end{itemize}

\vspace{.1in}
\small
Kinematically fit event, constraining $M_{top} = 175$~\GeVcc
\tiny
\begin{itemize}
	\item Require $\chi^2 < 10$
	\item[$\Rightarrow$] Left with 61 events 
\end{itemize}

\pagebreak

\tit{Measurement of $P_T$}

Measurements on lepton-side and jet-side are \Red{strongly
correlated!}

\begin{center}
\epsfig{file=correlations.eps}
\end{center}

\tiny
\begin{itemize}
\item Make measurement using only \Red{jet-side} top quarks
\end{itemize}

\pagebreak

\tit{$P_T$ Response Functions}

\small
Measured $P_T$\ smearing using MC/detector simulation

\begin{center}
\epsfig{file=res4.eps}
\end{center}

\tiny
\begin{itemize}
	\item Use standard HERWIG MC calculations
	\item Most smearing arises from incorrect jet assignments
\end{itemize}
\pagebreak

\tit{Uncorrected $P_T$\  Distribution}

\begin{center}
\epsfig{file=smear.eps}
\end{center}

\tiny
\begin{itemize}
	\item 61 events pass selection criteria
	\item Background distribution normalized to estimated rate
	\begin{itemize}
		\item We estimate $N_{bgd}=31.9\pm 4.6$\ events
	\end{itemize}
\end{itemize}

\pagebreak

\tit{Resulting Fitted $P_T$\ Distribution}

\small
Perform unbinned likelihood fit 
\tiny
\begin{itemize}
	\item Include four response functions and bkg shapes
	\item Fit tagged and untagged events with different templates
	\item Use ``bootstrap'' technique to minimize assumptions 
	about shape of $P_T$ spectrum \Red{within each true bin}
	\item Define
\begin{eqnarray}
		R_i \equiv {{\rm fraction\ in\ {\it i}th\ bin}\over{
			\sigma_{\mttbar}}} \nonumber
\end{eqnarray}
\end{itemize}
\small
Apply $P_T$-dependent acceptance correction
\tiny
\begin{itemize}
	\item Acceptance increases with $P_T$
\\[0.05in]
\end{itemize}

\tiny
\begin{eqnarray}
R_1 & = & 0.21^{+0.22}_{-0.21}\nonumber \\
R_2 & = & 0.45^{+0.23}_{-0.23}\nonumber \\
R_3 & = & 0.34^{+0.14}_{-0.12}\nonumber  \\
R_4 & = & 0.000^{+0.031}_{-0.000} \nonumber
\end{eqnarray}

\pagebreak

\tit{Confidence Level Interval on $R_4$}

Obtain \Red{$R_4^{\mathrm{fit}}=0$} (fraction of top with $P_T>225$~\GeVc)
\tiny
\begin{itemize}
	\item Use non-Bayesian technique to infer ``true'' size of $R_4$
	\item Set a 95\%\ CL limit using a MC technique
	\begin{itemize}
		\item Analyze samples of MC events with varying $R_4^{\mathrm{true}}$. 
		\item Smear $R_4^{\mathrm{true}}$ in each with
		Gaussian distribution with a width equal to 
		systematic uncertainty
		\item Determine value of $R_4^{\mathrm{true}}$ where 
		only 5\% of the MC samples have $R_4^{\mathrm{fit}}=0$
\\[0.03in]
	\end{itemize}
\end{itemize}

\tiny
\begin{center}
CDF PRELIMINARY\\
\begin{tabular}{|c|c|}
\hline
Systematic Effect & $\delta(R_4)$ \\[0.05in]
\hline
Background Model & $\pm 0.0028$ \\
Jet Energy Scale & ${}^{+0.0007}_{-0.0042}$ \\
No Initial State Radiation & $\pm 0.0045$ \\
Final State Radiation & $\pm 0.0095$ \\
Flat $P_T$ Spectrum & $\pm 0.0157$ \\
$m_t$ = 180~GeV & -0.0160 \\
\hline
\end{tabular}
\end{center}
\small

\pagebreak

\tit{95\% Confidence Level Upper Limit}

\begin{center}
\epsfig{file=find95_new.eps}
\end{center}

\vspace{0.25in}

\tiny
Agrees with result obtained by integrating the likelihood function
\begin{itemize}
	\item Including systematics, $R_4 < 0.16$ at 95\% CL
\end{itemize}

\pagebreak

\begin{center}
\Red{Top Quark Differential Cross Section}
\end{center}
\small
\begin{eqnarray}
R_1+R_2 & = & 0.66^{+0.17}_{-0.17}\mathrm{(stat)}
^{+0.06}_{-0.06}\mathrm{(syst)}\nonumber \\[0.10in]
R_4 & < & 0.16~\mathrm{at~95\%~C.L.}  \nonumber
\end{eqnarray}
\begin{center}
\epsfysize=4.0in
\epsffile{sm.eps}
\end{center}
\tiny
\begin{center}
\begin{tabular}{|c|l|}
\hline
$P_T$ Bin & Measured Fraction of Top Quarks \\
\hline
$0<P_T<75$~GeV/c & $R_1 = 0.21^{+0.22}_{-0.21}\mathrm{(stat)}
^{+0.10}_{-0.08}\mathrm{(syst)}$\\
$75<P_T<150$~GeV/c & $R_2= 0.45^{+0.23}_{-0.23}\mathrm{(stat)}
^{+0.04}_{-0.07}\mathrm{(syst)}$\\
$150<P_T<225$~GeV/c & $R_3= 0.34^{+0.14}_{-0.12}\mathrm{(stat)}
^{+0.07}_{-0.05}\mathrm{(syst)}$\\
$225<P_T<300$~GeV/c & $R_4=0.000^{+0.031}_{-0.000}\mathrm{(stat)}
^{+0.019}_{-0.000}\mathrm{(syst)}$\\
\hline
\end{tabular}
\end{center}

\pagebreak
%
%  Single Top Production
%
\tit{Single Top Production}

\small
Single top production is a much lower rate process
\tiny
\begin{itemize}
	\item Sensitive to $\Gamma_{t}$\
	\item Also could have contributions from non-SM sources
			\\[0.05in]
\end{itemize}

\small
There are two primary SM production processes
\tiny
\begin{enumerate}
	\item $t$-channel $W-g$\ fusion $\Rightarrow W^+ b q$\ final state
	\item $s$-channel $W^\ast$\ process 
		$\Rightarrow W^+ b \bar{b}$\ final state
			\\[0.01in]
\end{enumerate}

\begin{center}
\epsfysize=3.0in
\epsffile[30 140 520 630]{single_top_production_diagrams.ps}
\end{center}

\begin{itemize}
	\item Predicted cross sections are $1.7\pm0.3$\ and
$0.7\pm0.1$~pb
\end{itemize}
\pagebreak
%
%  Search for two processes
%
\tit{Search Technique}

\small
Kinematics of production processes different
\tiny
\begin{itemize}
	\item Use the same selection for both processes
	\begin{itemize}
		\item 1, 2 or 3 jets with $E_T>15$~Gev and $|\eta|<2.0$
		\item At least one $b$-tagged jet
		\item Require $140\le M_{top}\le 210$~\GeVcc
	\end{itemize}
	\item Fit $H_T$\ distribution with signal and background
terms
\begin{eqnarray}
	H_T \equiv \sum_{\rm partons} E_T
\nonumber
\end{eqnarray}
\end{itemize}
\tiny
\begin{center}
\begin{tabular}{lcc}
			&  $W^\ast$	&	$W$-gluon \\[0.05in]
\hline \\
$\sigma_{theory}$\ (pb)		&   $0.73\pm0.10$	&  $1.7\pm0.3$ \\
Integrated luminosity (\invpb)	&  $106\pm4$		&  $106\pm4$   \\
$W+n$~jet acceptance (\%)	&  $ 4.5\pm0.7$		&  $6.7\pm1.0$ \\
SVX $b$-tag efficiency (\%)	&  $37.5\pm3.1$		& $24.8\pm2.0$ \\[0.05in]
\hline \\
Number of expected events	&  $1.3\pm0.3$		&  $3.0\pm0.6$ \\
\end{tabular}
\end{center}

\vspace{.2in}
		
\pagebreak

\tit{Top Mass Reconstruction}

\vspace{.5in}

\begin{center}
\epsfysize=5.5in
\epsffile[30 140 520 630]{single_top_top_mass.ps}
\end{center}

\pagebreak
\tit{$H_T$\ Reconstruction}

\small
The variable $H_T$\ is an effective discriminator
\tiny
\begin{itemize}
	\item QCD Background
	\item \ttbar\ background
	\item Single top signal
\end{itemize}
\vspace{.5in}

\begin{center}
\epsfysize=5.0in
\epsffile{ht_sig_bkgd.eps}
\end{center}

\pagebreak
%
%  Results of search
%
\tit{Results of Search}

\small
Observed 65 events in this sample
\tiny
\begin{itemize}
	\item Largest single background are mistags
	\begin{itemize}
		\item $t\bar{t}$\ itself is a \Red{problem}\ now
	\end{itemize}
\end{itemize}

\begin{center}
\begin{tabular}{lc}
Process			&	Event Yield \\[0.05in]
\hline \\
Mistags				&	$ 25.9\pm7.5$	\\
$W b \bar{b} + W c \bar{c}$	&	$ 28.7\pm7.5$	\\
$W c$				&	$ 17.2\pm6.2$	\\
Non-$W$\			&	$ 12.1\pm4.1$	\\
Miscellaneous			&	$  5.1\pm0.9$	\\
\hline \\
After $M_t$\ cut		&       $ 54\pm11$      \\
\hline \\
$t\bar{t}$			&	$ 8.4\pm2.7$	\\
$W$-gluon			&	$ 3.0\pm0.6$	\\
$W^\ast$			&	$ 1.3\pm0.3$	\\
\hline \\
Total expected			&	$67 \pm 11$	\\
Observed			&	   65    	\\
\end{tabular}
\end{center}

\small
Not yet sensitive to SM single top rate
\tiny
\begin{itemize}
	\item Can set limits on total single top rate
\end{itemize}
\pagebreak


%
%  Single top from W* production
%
\tit{Single Top Production Cross Section Limits}

\small
Use $H_T$\ distribution to fit signal and background shapes
\tiny
\begin{itemize}
	\item Set upper limit using a Bayesian technique
	\item Fit gives $\sigma_t < 13.5$~pb at 95\%\ CL
		\\[0.1in]
\end{itemize}

\begin{center}
\epsfysize=4.0in
\epsffile{ht_data_mc.eps}
\end{center}

\small
Still well away from SM rate
\tiny
\begin{itemize}
	\item Can conclude that there is no huge anomaly
	\item It is a feasable measurement for Run II
	\begin{itemize}
		\item Can get $S/N = 2.9$\ on $W+2,3$\ jet sample
	\end{itemize}
\end{itemize}

\pagebreak
%
%  Wrap up
%
\tit{Run II Forecasts}

\small
Run II will start this summer at $\sqrt{s}=2.0$~TeV
\tiny
\begin{itemize}
	\item CDF will begin with engineering run (no SVX II)
	\item Both detectors will be completed by end of 2000
	\item Physics running will commence in 2001
\\[0.05in]
\end{itemize}

\small
Will be worth the wait
\tiny
\begin{itemize}
	\item Begin with $\sim 3$~\invfb/year per detector
	\item Finish up with $\sim 5$~\invfb/year 
	\item Literal ``Top Factory'' with 
	\begin{itemize}
		\item 300 dilepton events
		\item 3000 tagged lepton+jet events
		\item 1500 events in ``mass sample''
	\end{itemize}
\end{itemize}

\pagebreak

\tit{Top Physics Goals in Run II}

\small
Mass analysis uncertainties scale with statistics
\tiny
\begin{itemize}
	\item Can expect $\delta M_t\sim 3.0$\~\GeVcc
	\item With $\delta M_W \sim 40$~\MeVcc
\begin{eqnarray}
{{\delta M_{Higgs}}\over{M_{Higgs}}} \sim 40\%
\nonumber
\end{eqnarray}
	\item Powerful ``pointer'' for LHC searches
\\[0.05in]
\end{itemize}

\small
Measure angular correlations and decay kinematics
\tiny
\begin{itemize}
	\item Polarization of $W^+$\ will be measurable
	\item Spin correlations (expect 90\%) also detectable
\\[0.05in]
\end{itemize}

\small
Single top production 
\tiny
\begin{itemize}
	\item Measure $\sigma_t$\ with 10\%\ uncertainty
	\item Measure $V_{tb}$\ with 12\%\ uncertainty
\\[0.05in]
\end{itemize}

	
\pagebreak

\tit{Summary}

\small
Debut of top using Run I data coming to close
\tiny
\begin{itemize}
	\item Have seen that it looks much like a SM fermion
	\item But top mass scale is enigmatic
			\\[0.05in]
\end{itemize}

\small
All this sets the stage for Run II
\tiny
\begin{itemize}
	\item Run for 2-4 years, with goal of $\sim6$~\invfb
	\begin{itemize}
	\item[$\Rightarrow$] Increase top quark sample $\times 50$
			\\[0.05in]
	\end{itemize}
\end{itemize}

\small
By the time next generation collider turns on,
\tiny
\begin{itemize}
	\item Top will be pretty well-studied
	\begin{itemize}
		\item Reveal some property that points toward a more 
		complete theory?
		\item Will at least be an important background
	\end{itemize}
	\item Will be able to reconstruct millions at the LHC!
	\begin{itemize}
		\item It will become the ``high-statistics'' probe of
	the next energy scale
	\end{itemize}
\end{itemize}

\end{document}
