Test of lepton flavor universality in semileptonic B+ c meson decays in proton-proton collisions at √s = 13 TeV

Abstract

A measurement of the ratio of branching fractions in the , decay channel is presented. This measurement uses a sample of proton-proton collision data collected at a center-of-mass energy of by the CMS experiment in 2018, corresponding to an integrated luminosity of . The measured ratio, , agrees with the value of predicted by the standard model, which assumes lepton flavor universality. By testing lepton flavor universality, this measurement is a probe of new physics using mesons, which are currently only produced at the LHC.