Forward backward asymmetries of lepton pairs in events with a large transverse momentum jet at hadron colliders

Abstract

We discuss forward-backward charge asymmetries for lepton-pair production in association with a large-transverse-momentum jet at hadron colliders. The lepton charge asymmetry relative to the jet direction AjFB gives a new determination of the effective weak mixing angle sin2lept eff M2 Z with a statistical precision after cuts of 10 3 (8 10 3) at LHC (Tevatron). This is to be compared with the current uncertainty at LEP and SLD from the asymmetries alone, 2 10 4. The identification of b jets also allows for the measurement of the bottom-quark–Z asymmetry AbFB at hadron colliders, the resulting statistical precision for sin2lept eff M2 Z being 9 10 4 (2 10 2 at Tevatron), also lower than the reported precision at e+ e- colliders, 3 10 -4.