Study of the kinematic dependences of Λ [0 over b] production in pp collisions and a measurement of the Λ [0 over b] → Λ [+ over c] π[superscript −] branching fraction

• Main Authors: LHCb collaboration (Author), Counts, Ian Thomas Hunt (Contributor), Ilten, Philip James (Contributor), Williams, M. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: Springer-Verlag Berlin Heidelberg, 2014-10-24T16:45:54Z.
• Subjects: Article
• Online Access: Get fulltext

 The kinematic dependences of the relative production rates, fΛ[0 over b]/fd , of Λ [0 over b] baryons and B 0 mesons are measured using Λ [0 over b] → Λ [+ over c] π − and B¯¯0 →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, p T, and pseudorapidity, η, of the beauty hadron, in the studied kinematic region 1.5 < p T < 40 GeV/c and 2 < η < 5. Using a previous LHCb measurement of fΛ0b/fd in semileptonic decays, the branching fraction ℬ(Λ [0 over b]  → Λ [+ over c] π −) = (4.30 ± 0.03 − 0.11 + 0.12  ± 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 B¯¯0 →D+π− branching fraction. This is the most precise measurement of a Λ [0 over b] branching fraction to date.