Measurement of the B0–B0 and B0s –B0s production asymmetries in pp collisions at √s = 7 TeV

Abstract The B ¯ 0 – B 0 and B ¯ s 0 – B s 0 production asymmetries, A P ( B 0 ) and A P ( B s 0 ) , are measured by means of a time-dependent analysis of B 0 → J / ψ K ⁎ 0 , B 0 → D − π + and B s 0 → 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 B 0 and B s 0 mesons within the LHCb acceptance. The production asymmetries, integrated over p T and η in the range 4 p T 30 GeV / c and 2.5 η 4.5 , are determined to be A P ( B 0 ) = ( − 0.35 ± 0.76 ± 0.28 ) % and A P ( B s 0 ) = ( 1.09 ± 2.61 ± 0.66 ) % , where the first uncertainties are statistical and the second systematic.