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This note presents a new measurement of $p\bar p \to t \bar tX$ production |
We present a new measurement of $p\bar p \to t \bar tX$ production |
at $\sqrt{s}=1.96$ TeV using 4951.86 pb$^{-1}$ of data collected with the |
at $\sqrt{s}=1.96$ TeV using 4951.86 pb$^{-1}$ of data collected with the |
D\O\ detector between 2002 and 2010. We focus on the final state |
D0 detector between 2002 and 2010. We focus on the final state |
where the $W$ boson from one of the top quarks decays into a |
where the $W$ boson from one of the top quarks decays into a |
$\tau$ lepton and its associated neutrino, while the other W boson decays into |
$\tau$ lepton and its associated neutrino, while the other $W$ boson decays into |
a quark-antiquark pair. We aim to select those events in which the |
a quark-antiquark pair. We aim to select those events in which the |
$\tau$ lepton subsequently decays hadronically, meaning to one or three charged hadrons, zero |
$\tau$ lepton subsequently decays hadronically, meaning to one or more charged hadrons, zero |
or more neutral hadrons and a tau neutrino. We use a neural network b-tagging algorithm |
or more neutral hadrons and a tau neutrino. We train a topological neural network |
as well as a topological neural network to enhance signal over the background. For a top quark |
as the method to enhance signal over the background. For a top quark |
mass of 172.5 GeV the preliminary result for the measured cross section is: |
mass of 172.5 GeV we measure the cross section to be: |
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\begin{center}\[\sigma (t\overline{t}) = |
\begin{center}\[\sigma (t\overline{t}) = |
8.46\;\;_{-1.04}^{+1.06}\;\;({\textrm{stat}})\;\;_{-0.88}^{+0.92}\;\;({\textrm{syst}})\;\;\pm 0.3\;\;({\textrm{lumi}})\;\; \rm{pb.}\] |
8.46\;\;_{-1.04}^{+1.06}\;\;({\textrm{stat}})\;\;_{-0.78}^{+0.84}\;\;({\textrm{syst}})\;\;\pm 0.3\;\;({\textrm{lumi}})\;\; \rm{pb.}\] |
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