Measurement of B meson production cross-sections in proton-proton collisions at √s = 7 TeV

The production cross-sections of B mesons are measured in pp collisions at a centre-of-mass energy of 7 TeV, using data collected with the LHCb detector corresponding to a integrated luminosity of 0.36 fb⁻¹. The B⁺, B⁻ and B⁰_s mesons are reconstructed in the exclusive decays B⁺ → J/ψ K⁺, B⁰ → J/ψ K*⁰ and B⁰_s → J/ψφ‚ with J/ψ → K*⁰ → K⁺π⁻ and φ → K⁺K⁻. The differential cross-sections are measured as functions of B meson transverse momentum p_T and rapidity y, in the range 0 < p_T < 40 GeV/c and 2.0 < y < 4.5. The integrated cross-sections in the same p_T and y ranges, including charge-conjugate states, are measured to be σ(pp → B⁺ + X) = 38.9 ± 0.3 (stat.) ± 2.5 (syst.) ± 1.3 (norm.) μb, σ(pp → B0 + X) = 38.1 ± 0.6 (stat.) ± 3.7 (syst.) ± 4.7 (norm.) μb, σ(pp → B⁰_s + X) = 10.5 ± 0.2 (stat.) ± 0.8 (syst.) ± 1.0 (norm.) μb, where the third uncertainty arises from the pre-existing branching fraction measurements.