This thesis documents the measurement of the $t\bar t$ production 
cross section using events with one charged lepton and jets from 
$p\bar p$ collisions at a center-of-mass energy of 1.96~$\Tev$. A 
$b$-tagging algorithm based on the probability of displaced tracks 
coming from the event interaction vertex is applied to identify $b$ 
quarks from top decay. 
Using 318~$\ipb$ of data collected with the {\CDFII} detector, we 
measure the $t\bar t$ production cross section in events with at 
least one restrictive (tight) $b$-tagged jet and obtain 
$8.9^{+1.0}_{-1.0}$(stat.)$^{+1.1}_{-1.0}$(syst.)~\pb. 
The cross section value a\-ssu\-mes a top quark mass of 
$m_{t}=178~\Gevcc$ in the acceptance corrections. The dependence of 
the cross section on $m_t$ is presented in the paper.
This result is consistent with other \CDF\ measurements of the 
$t\bar t$ cross section using different samples and analysis techniques, 
and has similar systematic uncertainties. We have also performed 
consistency checks by using the $b$-tagging probability function to vary 
the signal to background ratio and also using events that have at least 
two $b$-tagged jets.



Posted to /cdf/pub/thesis/cdf8772_ttbar_xsect_jetprob.ps
    http://www-cdf.fnal.gov/thesis/cdf8772_ttbar_xsect_jetprob.ps

Posted by palencia