Measurement of the charge asymmetry in B-+/- -> phi K +/- and search for B-+/- -> phi pi(+/-) decays

Abstract

The CP-violating charge asymmetry in B± → φK± decays is measured in a sample of pp collisions at 7 TeV centre-of-mass energy, corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment. The result is ACP (B± → φK±) = 0.022 ± 0.021 ± 0.009, where the first uncertainty is statistical and the second systematic. In addition, a search for the B± → φπ± decay mode is performed, using the B± → φK± decay rate for normalization. An upper limit on the branching fraction B(B± → φπ±) < 1.5 × 10−7 is set at 90% confidence level.