Measurement of the ttbar production cross section in ppbar collisions at sqrt(s)=1.96 TeV using events with large missing transverse energy and jets

TL;DR

This paper measures the top-antitop quark pair production cross section in proton-antiproton collisions at 1.96 TeV, using a novel event selection that enhances tau decay contributions and employs neural networks for signal discrimination.

Contribution

It introduces a measurement method that vetoes explicit electron and muon signatures, focusing on tau-rich decay channels, and utilizes neural networks for improved background discrimination.

Findings

Measured cross section: 7.99 pb with uncertainties

Consistent with Standard Model predictions

Enhanced sensitivity to tau decay channels

Abstract

In this paper we report a measurement of the ttbar production cross section in ppbar collisions at sqrt(s)=1.96 TeV using data corresponding to an integrated luminosity of 2.2fb-1 collected with the CDF II detector at the Tevatron accelerator. We select events with significant missing transverse energy and high jet multiplicity. This measurement vetoes the presence of explicitly identified electrons and muons, thus enhancing the tau contribution of ttbar decays. Signal events are discriminated from the background using a neural network, and heavy flavor jets are identified by a secondary-vertex tagging algorithm. We measure a ttbar production cross section of 7.99 +/- 0.55(stat) +/- 0.76(syst) +/- 0.46(lumi) pb, assuming a top mass m_top = 172.5 GeV/c^2, in agreement with previous measurements and standard model predictions.