Measurement of B Meson Production Fraction Ratios in Proton-Proton Collisions at √s=13 TeV Using Open-Charm and Charmonium Decays

Abstract

Production fraction ratios of B+, B-0, and B-s(0) mesons are measured in proton-proton collisions at root s = 13 TeV using a special dataset recorded in 2018 with high-rate triggers designed to collect an unbiased sample of 10(10) b hadrons with the CMS experiment at the LHC. These data allow the study of the opencharm decays of B mesons (B(s) -> pi D-(s) where the D meson decays into fully hadronic final states. By utilizing known branching fractions and precise theoretical calculations, production fraction ratios as functions of B meson transverse momentum (p(T)) and rapidity (y) are measured using open-charm decays in the kinematic range of 8 < p(T) < 60 GeV and vertical bar y vertical bar < 2.25. In addition, the same dataset is used to measure the relative production fraction ratios with the charmonium decay channels [B-(s) -> XJ/psi with X indicating a K+, K*(892)(0), or phi(1020) meson] where the J/psi meson decays into a pair of muons. The open-charm results are used to normalize the relative production fraction ratios obtained from the charmonium samples. Measurements of the ratios of branching fractions of B meson decays to charmonium and open-charm final states are also reported, which will improve the world-average values of these ratios. Finally, we test isospin invariance in B meson production in proton-proton collisions and observe that it holds within the experimental precision.