B-Hadron Production Asymmetries At LHCb

Using a data sample corresponding to an integrated lumunosity of 1.0 $fb^{−1}$ , collected by LHCb in pp collisions at a centre-of-mass energy of 7 TeV, the $B^0$ and $B^{0}_{s}$ production asymmetries, AP($B^0$) and AP($B^{0}_{s}$), are determined. These quantities are measured by means of an un-tagged time-dependent analysis of B 0 → J/$ψK^{*0}$ , $B^0$ → $D^− π^+$ and $B^{0}_{s}$ → $D^{−}_{s}$ $\pi^+$ decays. The production asymmetries are measured as a function of the trasverse momentum and pseu- dorapidity of the $B^0$ and $B^{0}_{s}$ mesons. Finally, the total production asymmetries integrated over $pT$4 and η in the range 4 < $pT$ < 30 GeV/c and 2.5 < η < 4.5 are determined and they are found to be $A_P$($B^0$) = (−0.35 ± 0.76 ± 0.28)% and $A_P$($B^{0}_{s}$) = (1.09 ± 2.61 ± 0.61)%, where the first uncertainties are statistical and the second systematic.