Observation of the decay B0s→D0φ

Abstract

First observation of the decayB0s→D0φis reported usingppcollision data, corresponding to an inte-grated luminosity of 1.0 fb−1, collected by the LHCb experiment at a centre-of-mass energy of 7 TeV. Thesignificance of the signal is 6.5 standard deviations. The branching fraction is measured relative to thatof the decayB0s→D0K∗0to beB(B0s→D0φ)B(B0s→D0K∗0)=0.069±0.013(stat)±0.007(syst).The first measurement of the ratio of branching fractions for the decaysB0s→D0K∗0andB0→D0K∗0is found to beB(B0s→D0K∗0)B(B0→D0K∗0)=7.8±0.7(stat)±0.3(syst)±0.6(fs/fd),where the last uncertainty is due to the ratio of theB0sandB0fragmentation fractions.