Study of the kinematic dependences of Λ⁰_b production in pp collisions and a measurement of the Λ⁰_b → Λ⁺_cπ⁻ branching fraction

The kinematic dependences of the relative production rates, fΛ0b/fd, of Λ0b baryons and B0 mesons are measured using Λ0 b → Λ+c π− and B0→ D+π− decays. The measurements use proton-proton collision data, corresponding to an integrated luminosity of 1 fb−1 at a centre-of-mass energy of 7 TeV, recorded in the forward region with the LHCb experiment. The relative production rates are observed to depend on the transverse momentum, pT, and pseudorapidity, η, of the beauty hadron, in the studied kinematic region 1.5 < pT < 40 GeV/c and 2 < η < 5. Using a previous LHCb measurement of fΛ0b/fd in semileptonic decays, the branching fraction BΛ0b → Λ+c π−=4.30±0.03 +0.12 −0.11±0.26± 0.21 ×10−3 is obtained, where the first uncertainty is statistical, the second is systematic, the third is from the previous LHCb measurement of fΛ0b/fd and the fourth is due to the B 0 → D+π − branching fraction. This is the most precise measurement of a Λ0b branching fraction to date.