Measurement of the ratio of branching fractions B(B0→K*0γ)/B(B0s→ϕγ)

Abstract

The ratio of branching fractions of the radiative B decays B0→K*0γ and B0s→ϕγ has been measured using 0.37 fb−1 of pp collisions at a center of mass energy of √s=7 TeV, collected by the LHCb experiment. The value obtained is B(B0→K*0γ)B(B0s→ϕγ)=1.12±0.08+0.06+0.09−0.04−0.08, where the first uncertainty is statistical, the second systematic, and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average for B(B0→K*0γ)=(4.33±0.15)×10−5, the branching fraction B(B0s→ϕγ) is measured to be (3.9±0.5)×10−5, which is the most precise measurement to date.