Measurement of the top quark-pair production cross section with ATLAS in pp collisions at $\sqrt{s}=7\TeV$

The ATLAS Collaboration

Paper

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at $\sqrt{s}=7\TeV$

Abstract

A measurement of the production cross-section for top quark pairs(

) in

collisions at

is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron

or muon

) with large missing transverse energy and at least four jets, and dilepton (

) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-

Standard Model processes are estimated using data-driven methods and determined to be

events and

events, respectively. The kinematic properties of the selected events are consistent with SM

production. The inclusive top quark pair production cross-section is measured to be

pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.