Chapter 2.2 - Properties of the Top Quark
The complete Chapter 2.2 document is available
here.
Figures
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Figure 2.1
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$\Delta\phi$ vs. $\met$ in the dilepton sample. The small grey dots
are the result of a $t\overline{t}$ Monte Carlo simulation with
${\rm M_{top}} = 175$ GeV/c$^{2}$.
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Figure 2.2
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The proper time distribution for the $b$-tagged
jets in the signal region (W+$\ge$ 3 jets). The open
histogram shows the expected
distribution of $b$'s from 175 GeV/$c^2$ $\ttbar$ Monte Carlo simulation. The
shaded histogram indicates the background in W+jet events.
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Figure 2.3 -
Top Left:
The jet multiplicity distribution in SVX tagged W+jet
events. Closed
circles are number of events before $b$-tagging, dark triangles are number
of $b$-tagged events
in each bin and hatched areas are the background prediction
for the number of tagged events and its uncertainty.
Top Right:
Mass spectrum for $b$-tagged lepton+jet events in 110 pb$^{-1}$ of data. The
shaded area is the expectation from background. The dashed curve is
from background plus top production. The likelihood fit is shown as
an inset.
Bottom Left:
The jet multiplicity distribution for the all-hadronic mode. The dark
triangles represent the observed number of $b$-tags in each jet multiplicity
bin and the
hatched areas represent the background prediction as well as its
estimated uncertainty.
Bottom Right:
Mass spectrum for all-hadronic
$b$-tagged events in 110 pb$^{-1}$ of data. The
shaded area is the expectation from background. The histogram is
from background plus top production.
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Figure 2.4
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The measured cross section for $t\bar{t}$ production for each of
the separate production channels measured at CDF as well as the
combined lepton+jets and dilepton measurements. The vertical line represents
the spread of the central values of the three most current theoretical
calculations evaluated at a top mass of 175 GeV/$c^2$.
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Figure 2.5
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The optimized lepton+jets top quark mass plot for each of the
four data samples. The insert shows the -$\Delta$log(likelihood)
for the data in comparison to mass spectra derived from Monte Carlo
samples of various $m_t$. This technique results
in a measured top quark mass of
${\rm 176.8\pm 4.4~(stat.)\pm 4.8~(syst.)}$ GeV/c$^{2}$
-- a 30\% improvement over the old analysis.
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Figure 2.6
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The $M_{jj}^W$ distribution is shown for data (solid),
expected top+background (dashed), and background (shaded),
for W+4 jet events which contain two $b$-tagged jets. The value
of $M_{jj}^W$ is 79.8 $\pm$ 6.2 GeV/c$^2$. The top mass from this subsample
has been determined to be 174.8 $\pm$ 9.7 GeV/c$^2$.
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Figure 2.7
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The $\cos \theta^*_e$ distribution for 1000 events and
fit to the Standard Model hypothesis $\sim$ 30\% $W_{\rm left}$ +
70\% $W_{\rm long}$.
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Figure 2.8
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A hypothetical $M_{t\bar{t}}$ spectrum with an 800 GeV/c$^2$ Z$^\prime$ topcolor
boson. The rate is based on the theoretical predicted cross section for
$t\bar{t}$ production and Z$^\prime$ production \protect\cite{chill} with 2 fb$^{-1}$.