fig01-d0_isometric.eps
Cut away isometric view of the \dzero\ detector.


fig02-etw.eps
$\et^W$ distribution for
Monte Carlo $W$+jets events (solid histogram)
and for QCD multijet background data (dashed histogram).
All selection cuts are applied except for the $\et^W$ cut.
The arrow shows the cut value.
(The normalizations are taken from the result of the LB
fit to the data, as described in \secref{fits-to-data}, with
channels combined as described in \secref{vbls-and-binning}.  The
models used to simulate the data are described in \secref{mcsim}.)


fig03-etaw.eps
$|\eta^W|$ distribution for data (histogram), predicted
signal plus background (filled circles), and background alone (open triangles).
All selection cuts are applied except for the $\eta^W$ cut.
The arrow shows the cut value.
(The normalizations are as in \figref{fg:et_l}.)


fig04-out-of-cone.eps
The measured jet energies for quarks from
$W\rightarrow q\qbar$ in $t\tbar$ MC are plotted
against the corresponding parton energies.
Radiation outside of the jet cone
causes the measured jet energy to be
lower than the energy at the parton level.  The dashed line
is drawn along the diagonal, and
the solid line is a linear fit to the points.   This plot is based on
\progname{HERWIG} fragmentation with $|\deteta^{\jet}| < 0.2$.

 
fig05-smear_mu_v2.eps
Correlation between the measured momentum and the
true momentum of the tag muon
in Monte Carlo $t\tbar$ events.  The curve is the result of an empirical fit,
$47.19 [1 - \exp (-0.03398 - 0.01593 p^\mu - 0.0005554 (p^\mu)^2)]$.


fig06-emu_enu_v2.eps
Correlation between the tag muon momentum and the total leptonic
energy from $b$~quark decay in \hbox{MC} $t\tbar$ events.  The curve is
the result of an empirical fit,
$1.313 + \exp (3.101 - 0.6528 p^\mu) + \exp (0.4622 - 0.06514 p^\mu)$.


fig07-scale_det_eta.eps
The energy scale deviation $\Delta S$ as a function
of $\deteta^{\jet}$ for (a) data and (b) Monte Carlo.  The curves are
empirical multigaussian fits to the points.


fig08-jetcorr-systematic.eps
The relative energy scale difference between data and MC as a
function of photon $\et$ after all jet corrections are applied.
The curves are the error band 
$\pm(2.5 \% + {0.5\gev})$.

 
fig09-jetcorr-zjets-all-applied.eps
Transverse energy balance for $(Z\rightarrow ee)+\jets$
events.  The vector $\vec{p}_T^{\,Z} + \sum_{\jets} \vec{E}_T^{\jet}$
is projected onto the angle bisector of the two electrons.  All
jet corrections are applied.  The curve is a Gaussian fit to the
histogram.

 
fig10-jetcorr-mccheck.eps
Masses of $W\rightarrow q\qbar$ and $t\rightarrow bq\qbar$
in $t\tbar$ MC with $m_t = 175\gevcc$, both (a), (b) with standard
corrections only and (c), (d) with all jet corrections.  The arrows
locate the input $W$~boson and top~quark masses.


fig11-ht2.eps
Plot of $H_{T2}$ for the 77-event candidate sample, compared
with the expectation for $m_t=175\gevcc$ signal plus background
(filled circles), signal alone (open squares),
and background alone (open triangles).
(The normalizations are as in \figref{fg:et_l}.)


fig12-w3j.eps
The variables $x_1 \ldots x_4$ used as input to the
top quark discriminants, for $W+3$ jet control samples.  Histograms
are data, and the circles are the expected signal + background mixture.


fig13-discrim-vars.eps
The variables $x_1 \ldots x_4$ used as input to the
top quark discriminants, for the 77-event candidate sample (histogram),
$\ttbar$ signal plus background for $m_t = 175\gevcc$ (filled circles),
signal alone (open squares), and background alone
(open triangles).
(The normalizations are as in \figref{fg:et_l}.)


fig14-dlb-and-dnn.eps
The discriminant variables (a)~$\DLB$ and (b)~$\DNN$ plotted
for the $m_t=175\gevcc$ $\ttbar$ (hatched) sample and
the simulated background (unhatched).
All histograms are normalized to unity.


fig15-discrim-vs-mass.eps
The discriminant variables (a)~$\DLB$ and (b)~$\DNN$ 
for $t\tbar$ Monte Carlo with
$m_t = 150\gevcc$ (dashed lines),
$m_t = 175\gevcc$ (solid lines), and
$m_t = 200\gevcc$ (dotted lines).
All histograms are normalized to unity.


fig16-discrim-data.eps
The discriminant variables (a)~$\DLB$ and (b)~$\DNN$ for
the 77-event candidate sample (histogram), $\ttbar$ signal plus
background (filled circles), and background alone (open triangles).
The binnings were chosen such that the predicted signal plus background
distribution would be approximately flat.


fig17-mc-tests.eps
Tests of kinematic fit method on $t\tbar$ Monte Carlo
samples ($m_t = 170\gevcc$, $e+\jets$ channel).  (a) Using
\progname{herwig} partons directly.  (b) Final state Monte Carlo
particles, after clustering into $R=0.5$ cones.  (c) After full
detector simulation and reconstruction.  The hatched plots show the
results for the correct jet permutation (regardless of whether or not it
has the lowest $\chisq$).
Displayed means and widths
are from a Gaussian fit, shown by the dashed curve.


fig18-chisq-corr.eps
Fit $\chisq$ distributions for the correct jet permutation
for $t\tbar$ Monte Carlo samples ($m_t = 170\gevcc$).  The dashed curve
is the $\chisq$ distribution for two degrees of freedom, normalized to
the area of the histogram.


fig19-mt-vs-channel.eps
Fitted mass distributions
for $t\tbar$ Monte Carlo samples ($m_t = 170\gevcc$)
for the jet permutation with the lowest $\chisq$.
Hatched
histograms show the results for the correct jet permutation
(regardless of whether or not it has the lowest $\chisq$).
Displayed means and widths
are from a Gaussian fit, shown by the dashed curve.


fig20-jet-scalecomp.eps
Fitted mass distributions
for $t\tbar$ Monte Carlo samples ($m_t = 170\gevcc$, $e+\jets$
channel).  With jets scaled (a) down and (b) up by $2.5\%+0.5\gev$.
Hatched histograms show the results for the correct jet permutation
(regardless of whether or not it has the lowest $\chisq$).
Displayed means 
are from a Gaussian fit, shown by the dashed curve.


fig21-mt-vs-mass.eps
Fitted mass distributions, all channels combined.
Shown is $t\tbar$ Monte Carlo with (a) $m_t = 150\gevcc$,
(b) $m_t = 170\gevcc$, and (c) $m_t = 190\gevcc$ and (d) background.
The hatched distributions are after the LB selection is applied.


fig22-minuitcomp.eps
Differences between the results obtained from
the \progname{minuit}-based fitter 
and 
the Lagrange-multiplier based fitter 
for (a) $\mfit$
and (b) $\chisq$.  (For $t\tbar$ Monte
Carlo with $m_t = 170\gevcc$, $e+\jets$ channel.)


fig23-resfunc2d.eps
Monte Carlo histograms for LB and NN analyses
for $t\tbar$ Monte Carlo with $m_t = 175\gevcc$, \progname{vecbos}
$W+\jets$ background, and QCD multijet background.  More top~quark-like
events are towards the top of the plots.


fig24-datanocut.eps
Fitted mass distributions for candidate events.
The hatched histograms show the LB subsample.


fig25-datacut.eps
Fitted mass distributions for candidate events with $\chisq < 10$.
The hatched histograms show the LB subsample.


fig26-chisq-comp.eps
Fit $\chisq$ distribution from data (histogram), the
expected $\ttbar$ signal + background (filled circles), and background
alone (open triangles).


fig27-allcand.eps
Fitted mass for all
events which pass the precuts and the $\chisq$ cut.
Filled circles are a mixture of $\ttbar$ signal
and background and open triangles are the background only,
both averaged between the results of the LB and NN analyses.


fig28-like-and-lb.eps
Negative log likelihood for (a) LB and (b) NN analyses.
The solid curve is a quadratic fit to the 9~points around the minimum;
the dashed curve is from fitting \eqref{eq:fdef} to all points in the
range 110--$230\gevcc$.  (c) Results of the LB fit for events passing
the LB selection.  The histogram is data, filled circles are a mixture
of $m_t=175\gevcc$ $\ttbar$ signal and background, normalized using the results
of the LB fit, and open triangles are background only.


fig29-lb-data-fail.eps
Results of the LB fit for events failing the LB selection.
The histogram is data, filled circles are a mixture
of $m_t=175\gevcc$ $\ttbar$ signal and background, normalized using the results
of the LB fit, and open triangles are background only.


fig30-nn-data.eps
Results of NN fit: (a) Data, (b) $m_t=172\gevcc$ $\ttbar$
signal plus background, normalized using the results of the NN fit.


fig31-ensembles.eps
Mass and pull distributions for 10,000 MC experiment ensembles
with compositions matching the fit results.  The dashed curves are
Gaussian fits.  For the mass distributions, the width is
the symmetric interval containing $68\%$ of the entries; for the pull
distributions, it is from the Gaussian fit.


fig32-minlnl.eps
Minimum $-\ln L$ distributions from the LB and NN ensembles.
The arrows show the values corresponding to the data fits.


fig33-ensemble-err.eps
Statistical error distributions from the LB and NN ensembles.
The arrows show the values corresponding to the data fits.


fig34-sigma-vs-mt-p.eps
Scatter plot of masses and statistical errors
from the LB ensemble.  The dashed lines of constant relative error
delimit the ``accurate subset'' (see text).


fig35-ensemble-relerr.eps
Relative error ($\sigma(m_t)/m_t$)
distributions from the LB and NN ensembles.
The arrows show the value corresponding to the data fits, and the
hatched regions show the definitions of the accurate subsets.


fig36-ensemble-acc.eps
Mass distributions for accurate subsets of ensembles.
The dashed curves are Gaussian fits.


fig37-prdpl1.eps
$\chisq$ plot for \progname{SQUAW} fixed-mass fits for event
58203, 4980.


fig38-prdpl2.eps
Average $\chisq/2$ plots (after LB selection)
for \progname{HERWIG} 
(filled circles) and
\progname{ISAJET} (open triangles) $\ttbar$ events.


fig39-prdpl3.eps
Average $\chisq/2$ plots (after LB selection)
for (a) \progname{VECBOS}
$W+\jets$ and (b) QCD multijet background samples.


fig40-prdpl4.eps
 68\% widths of ensemble mass distributions for different analyses.
Squares are for PL fits to the LB subset,
circles are for LB variable-mass fits,
and plus symbols are for the NN variable-mass fits.
Typical errors on the plotted values are between 0.5 and $1.0\gevcc$.


fig41-prdpl5.eps
Same as \figref{fg:prdpl4} for mean ensemble mass deviations.


fig42-prdpl6.eps
Pull distribution for LB subset fits to precut ensemble samples
with $m_t = 175\gevcc$.  The curve is a
Gaussian fit to the region $-3$ to $+3$.


fig43-prdpl7.eps
(a) $\chisq/2$ plots for the LB subset of the PR sample.
Data are the open squares, filled circles are the
prediction for a mixture of background and $175\gevcc$ top events,
and open triangles are the prediction for pure background.
The solid line joins the filled circles.
(b) Background-subtracted $\chisq/2$ plot for LB subsets.  Data are
the open squares, and filled circles
are the prediction for $175\gevcc$ top events.  The
dashed curve is a parabola fit near the minimum.


fig44-njets.eps
Number of jets in each event with $\et > 15\gev$ and $|\eta| < 2$
for (a) \progname{herwig} ($m_t = 170\gevcc$) and
(b) \progname{isajet} ($m_t = 170\gevcc$).
The histogram is data,
open triangles are expected background, and filled circles are expected
signal plus background.


fig45-mtw.eps
Transverse mass of the lepton and neutrino.
The histogram is data,
open triangles are expected background, and filled circles are expected
signal plus background.


fig46-kt.eps
Total transverse momentum $\kt$ of all objects used in the mass fit
(the highest four jets, the lepton, and the $\met$).
This is a vector sum.
The histogram is data,
open triangles are expected background, and filled circles are expected
signal plus background.


fig47-chisqfix.eps
$\chisq$ distributions from the 3C fit.  The histogram is data
(with two overflows),
open triangles are expected background, and filled circles are expected
signal plus background.


fig48-mtt.eps
Invariant mass distribution of the $t\tbar$ pair.
The histogram is data,
open triangles are expected background, and filled circles are expected
signal plus background.
(a) 2C fit, (b) 3C fit with $m_t=173.3\gevcc$.


fig49-ptt2.eps
Same as \figref{fg:mtt} for the transverse momenta of
the top quarks (two entries per event).


fig50-etat.eps
Same as \figref{fg:mtt} for the pseudorapidities
of the top quarks (two entries per event).


fig51-deta_tt.eps
Same as \figref{fg:mtt} for the difference in pseudorapidity
$\eta$ between the two top quarks.


fig52-dphi_tt.eps
Same as \figref{fg:mtt} for the difference in azimuthal angle
$\phi$ between the two top quarks.


fig53-xsecplot.eps
Comparison of the measured top quark mass and production
cross section with theoretical
calculations~\protect\cite{laenen}.