Paper detail

On the W+4 jets background to the top quark asymmetry at the Tevatron

We investigate the possibility that the W+4 jets background is a source of the anomalously large top-antitop (tt) charge asymmetry observed at the Tevatron. We simulate the tt reconstruction of the signal and background events at the matrix-element level and find that the reconstructed tt candidates from the W +4 jets background could give large forward-backward asymmetry. We suggest serious re-evaluation of the W+4 jets background for the tt candidate events by studying the distributions of the reconstructed tt systems in their rapidity difference, the transverse momentum of the top quark, and that of the tt system, which can differ significantly from those of the QCD tt production events especially at high tt invariant mass.