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Title: Measurements of top quark pair production cross section in proton anti-proton collisions at √s = 1.96 TeV in the τ + jets final state using 1 fb-1 of data

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/970066· OSTI ID:970066
 [1]
  1. Univ. of Oklahoma, Norman, OK (United States)

This dissertation presents a new measurement of p$$\bar{p}$$ → t$$\bar{t}$$X production at √s = 1.96 TeV using 974.2 pb-1of data collected with the D0 detector between 2002 and 2006. We focus on the final state where the W boson from one of the top quarks decays into a τ 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 τ lepton subsequently decays hadronically, meaning to one or three charged hadrons, zero or more neutral hadrons and a tau neutrino (the charge conjugate processes are implied in all of the above). The observable signature thus consists of a narrow calorimeter shower with associated track(s) characteristic of a hadronic tau decay, four or more jets, of which two are initiated by b quarks accompanying the W's in the top quark decays, and a large net missing momentum in the transverse plane due to the energetic neutrino-antineutrino pair that leave no trace in the detector media. The preliminary result for the measured cross section is: σ(t$$\bar{t}$$) = 6.9-1.2 +1.2(stat)-0.7+0.8(syst) ± 0.4 (lumi) pb. This indicates that our finding is consistent with the Standard Model prediction.

Research Organization:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC02-07CH11359
OSTI ID:
970066
Report Number(s):
FERMILAB-THESIS-2009-46; TRN: US1000729
Country of Publication:
United States
Language:
English