UNSPECIFIED (2014) Measurement of the forward-backward asymmetry in the distribution of leptons in tt¯ events in the lepton+jets channel. Physical Review D, 90: 072001. ISSN 1550-7998
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Abstract
We present measurements of the forward-backward asymmetry in the angular distribution of leptons from decays of top quarks and antiquarks produced in proton-antiproton collisions. We consider the final state containing a lepton and at least three jets. The entire sample of data collected by the D0 experiment during Run II of the Fermilab Tevatron Collider, corresponding to 9.7 fb−1 of integrated luminosity, is used. The asymmetry measured for reconstructed leptons is AlFB=(2.9±2.1(stat.)+1.5−1.7(syst.))%. When corrected for efficiency and resolution effects within the lepton rapidity coverage of |yl|<1.5, the asymmetry is found to be AlFB=(4.2±2.3(stat.)+1.7−2.0(syst.))%. We examine the dependence of AlFB on the transverse momentum and rapidity of the lepton. Combination with the asymmetry measured in the final states containing two leptons yields AlFB=(4.2±2.0(stat.)±1.4(syst.))%. The results are in agreement with predictions from the next-to-leading-order QCD generator mc@nlo, which predicts an asymmetry of AlFB=2.0% for |yl|<1.5.