Measurement of the [bar over B[superscript 0]] - B[superscript 0] and [bar over B [0 over s]] - B[0 over s] production asymmetries in pp collisions at √s = 7 TeV

Abstract

The [bar over B[superscript 0]] - B[superscript 0] and [bar over B [0 over s]] - B[0 over s] production asymmetries, A[subscript P](B[superscript 0]) and A[subscript P](B[0 over s]), are measured by means of a time-dependent analysis of B[superscript 0] → [J over ψK*[superscript 0]], B[superscript 0] → D[superscript −] π[superscript +] B[0 over s] → D[superscript -][subscript s] π[superscript +] decays, using a data sample corresponding to an integrated luminosity of 1.0 fb[superscript −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[superscript 0] and B[0 over s] mesons within the LHCb acceptance. The production asymmetries, integrated over p[subscript T] and η in the range 4 < p[subscript T] < 30 [GeV over c] and 2.5 < η < 4.5, are determined to be A[subscript P](B[superscript 0]) = (−0.35 ± 0.76 ± 0.28)% and A[subscript p](B[0 over s]) = (1.09 ± 2.61 ± 0.66)%, where the first uncertainties are statistical and the second systematic.