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 B 0 → K * 0 γ and B 0 s → ϕ γ has been measured using 0.37 fb − 1 of p p collisions at a center of mass energy of √ s = 7 TeV , collected by the LHCb experiment. The value obtained is B ( B 0 → K * 0 γ ) B ( B 0 s → ϕ γ ) = 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 f s / f d . Using the world average for B ( B 0 → K * 0 γ ) = ( 4.33 ± 0.15 ) × 10 − 5 , the branching fraction B ( B 0 s → ϕ γ ) is measured to be ( 3.9 ± 0.5 ) × 10 − 5 , which is the most precise measurement to date.