Measurement of the ttbar Production Cross Section with an in situ Calibration of b-jet Identification Efficiency

TL;DR

This paper reports a measurement of the top-quark pair-production cross section at 1.96 TeV using data from the Collider Detector at Fermilab, employing a novel in situ calibration method for b-jet identification efficiency.

Contribution

It introduces a new measurement technique that calibrates b-jet identification efficiency in situ by ensuring consistency between cross sections with different numbers of identified b-quarks.

Findings

Measured top-quark pair-production cross section: 8.5 ± 0.6 (stat) ± 0.7 (syst) pb.

Used data corresponding to 1.12/fb from the Collider Detector at Fermilab.

Developed a method to simultaneously determine cross section and b-jet ID efficiency.

Abstract

A measurement of the top-quark pair-production cross section in ppbar collisions at sqrt{s}=1.96 TeV using data corresponding to an integrated luminosity of 1.12/fb collected with the Collider Detector at Fermilab is presented. Decays of top-quark pairs into the final states e nu + jets and mu nu + jets are selected, and the cross section and the b-jet identification efficiency are determined using a new measurement technique which requires that the measured cross sections with exactly one and multiple identified b-quarks from the top-quark decays agree. Assuming a top-quark mass of 175 GeV/c^2, a cross section of 8.5+/-0.6(stat.)+/-0.7(syst.) pb is measured.