Measurement of the (B)over-bar(0)-B-0 and (B)over-bars(0)-B-s(0) production asymmetries in pp collisions at root s=7 TeV

Abstract

The B0 − B0 and B0 s − B0 s production asymmetries, AP(B0 ) and AP(B0 s ), are measured by means of a time-dependent analysis of B0 → J/ψK∗0 , B0 → D−π + and B0 s → D− s π + decays, using a data sample corresponding to an integrated luminosity of 1.0 fb−1 , collected by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. The measurements are performed as a function of transverse momentum and pseudorapidity of the B0 and B0 s mesons within the LHCb acceptance. The production asymmetries, integrated over pT and η in the range 4 < pT < 30 GeV/c and 2.5 < η < 4.5, are determined to be AP(B0 ) = (−0.35 ± 0.76 ± 0.28)% and AP(B0 s ) = (1.09 ± 2.61 ± 0.66)%, where the first uncertainties are statistical and the second systematic.