Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s) = 1.96 TeV

TL;DR

This paper reports a measurement of the top quark pair production cross section in proton-antiproton collisions at 1.96 TeV, using data from the Collider Detector at Fermilab, including the first observation with both b quarks identified.

Contribution

It provides the first observation of ttbar production with both b quarks identified and measures the cross section at 1.96 TeV with improved statistical significance.

Findings

Measured cross section: 8.7 pb with uncertainties.

First observation of ttbar with both b quarks identified.

Significance greater than 5 sigma for the combined b-quark identification sample.

Abstract

We present a measurement of the top quark pair production cross section in ppbar collisions at sqrt(s)=1.96 TeV using 318 pb^{-1} of data collected with the Collider Detector at Fermilab. We select ttbar decays into the final states e nu + jets and mu nu + jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178 GeV/c^2, we measure a cross section of 8.7 +-0.9 (stat) +1.1-0.9 (syst) pb. We also report the first observation of ttbar with significance greater than 5 sigma in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1 +1.6-1.4(stat)+2.0-1.3 (syst) pb.