Measurement of b-hadron fractions in 13 TeV pp collisions

Abstract

The production fractions of ${\overline{B}}_s^0$ and ${\Lambda }_b^0$ hadrons, normalized to the sum of $B^{-}$ and ${\overline{B}}^0$ fractions, are measured in 13 TeV pp collisions using data collected by the LHCb experiment, corresponding to an integrated luminosity of 1.67/fb. These ratios, averaged over the $b$-hadron transverse momenta from 4 to 25 GeV and pseudorapidity from 2 to 5, are $0.122\pm 0.006$ for ${\overline{B}}_s^0$, and $0.259\pm 0.018$ for ${\Lambda }_b^0$, where the uncertainties arise from both statistical and systematic sources. The ${\Lambda }_b^0$ ratio depends strongly on transverse momentum, while the ${\overline{B}}_s^0$ ratio shows a mild dependence. Neither ratio shows variations with pseudorapidity. The measurements are made using semileptonic decays to minimize theoretical uncertainties. In addition, the ratio of $D^{+}$ to $D^0$ mesons produced in the sum of ${\overline{B}}^0$ and $B^{-}$ semileptonic decays is determined as $0.359\pm 0.006\pm 0.009$, where the uncertainties are statistical and systematic.

Comments: 14 pages, 5 figures, see also https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2018-050.html