Measurement of the top quark-pair production cross section with ATLAS in pp collisions at s√=7 TeV.

THE ATLAS COLL. , G. AAD; MARIA TERESA DOVA ET AL.

EUROPEAN PHYSICAL JOURNAL C - PARTICLES AND FIELDS

SPRINGER

Lugar: Berlin; Año: 2011 vol. 71 p. 1577 - 1607

1434-6044

A measurement of the production cross-section for top quark pairs (tt) in pp collisions at s=7  TeV  is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron e or muon μ) with large missing transverse energy and at least four jets, and dilepton (ee, μμ or eμ) 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-tt Standard Model processes are estimated using data-driven methods and determined to be 12.2±3.9 events and 2.5±0.6 events, respectively. The kinematic properties of the selected events are consistent with SM tt production. The inclusive top quark pair production cross-section is measured to be tt=14531(stat)+42−27(syst) pb The measurement agrees with perturbative QCD calculations.