DØ Note 6441-CONF A Measurement of the Forward-Backward Asymmetry in the Production of B Mesons in pp̄ Collisions

We present a preliminary measurement of the forward-backward asymmetry in the production of B mesons, AFB(B ), using B → J/ψK decays in 10.4 fb of pp̄ collision data from Run II of the DØ Experiment at the Tevatron Collider. A non-zero asymmetry would indicate a preference for a particular flavor of b quark to be produced in the direction of the proton beam. AFB(B ) is extracted from a maximum likelihood fit to the difference between forwardand backward-produced B mesons, using a boosted decision tree to reduce background. Corrections are made for reconstruction asymmetries of the decay products. We measure AFB(B ) = [−0.26 ± 0.41 (stat.) ±0.17 (syst.)]% which is consistent with zero. Standard Model predictions based on next-to-leadingorder Monte Carlo calculations are in preparation.