Measurement of the ratio B(B0s→J/ψf0(980))/B(B0s→J/ψφ(1020)) in pp collisions at √s=7Te

Abstract

A measurement of the ratio of the branching fractions of the B0s meson to J/ψf0 (980) and to J/ψφ(1020) is presented. TheJ/ψ,f0(980),and φ(1020) are observed through their decays to µ+µ-, p+p-, and K+K-, respectively. The f0and the f are identified by requiring |Mp+p--974MeV| <50MeV and |MK+K--1020MeV| <10MeV. The analysis is based on a data sample of pp collisions at a centre-of-mass energy of 7TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3fb-1. The measu redratio is B(B0s→J/ψf0) B(f0→π+π−)B (B0s→J/ψφ) B(φ→K+K−) =0.140 ±0.008 (stat) ±0.023 (syst), where the first uncertainty is statistical and the second is systematic.