Measurement of CP -Violating and Mixing-Induced Observables in Bs0 →φγ Decays

Abstract

A time-dependent analysis of the Bs0→φγ decay rate is performed to determine the CP -violating observables Sφγ and Cφγ and the mixing-induced observable AφγΔ. The measurement is based on a sample of pp collision data recorded with the LHCb detector, corresponding to an integrated luminosity of 3 fb-1 at center-of-mass energies of 7 and 8 TeV. The measured values are Sφγ=0.43±0.30±0.11, Cφγ=0.11±0.29±0.11, and AφγΔ=-0.67-0.41+0.37±0.17, where the first uncertainty is statistical and the second systematic. This is the first measurement of the observables S and C in radiative Bs0 decays. The results are consistent with the standard model predictions.