Measurement of the ratio B(Bs0 ? J/?f0(980))/B(Bs0 ? J/??(1020)) in pp collisions at ?s=7 TeV

Abstract

A measurement of the ratio of the branching fractions of the Bs0 meson to J/?f0(980) and to J/??(1020) is presented. The J/?, f0(980), and ?(1020) are observed through their decays to ?+?-, ?+?-, and K+K-, respectively. The f0 and the ? are identified by requiring |M?+?--974 MeV|>50 MeV and |MK+K--1020 MeV|>10 MeV. The analysis is based on a data sample of pp collisions at a centre-of-mass energy of 7 TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb-1. The measured ratio is B(Bs0?J/?f0)B(f0??+?-)/B(Bs0?J/??)B(??K+K-) = 0.140±0.008(stat) ± 0.023(syst), where the first uncertainty is statistical and the second is systematic