Abstract

The ratio of branching fractions of the radiative B decays B-0 -> K-*0 gamma and B-s(0) -> phi gamma has been measured using an integrated luminosity of 1.0 fb(-1) of pp collision data collected by the LHCb experiment at a centre-of-mass energy of root s = 7 TeV. The value obtained is B(B-0 -> K-*0 gamma)/B(B-s(0) -> phi gamma) = 1.23 +/- 0.06 (stat.) +/- 0.04 (syst.) +/- 0.10 (f(s)/f(d)), where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions f(s)/f(d). Using the world average value for B(B-0 -> K-*0 gamma), the branching fraction B(B-s(0) -> phi gamma) is measured to be (3.5 +/- 0.4) x 10(-5). The direct CP asymmetry in B-0 -> K-*0 gamma decays has also been measured with the same data and found to be A(CP)(B-0 -> K-*0 gamma) = (0.8 +/- 1.7 (stat.) +/- 0.9 (syst.))%. Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.

Details

Actions