Charmless B \rightarrow VV decays at LHCb

Abstract

s meson decays into non-charmonium vector pairs are of particular interest to search for indirect CP violation. The analyses of two specific decays are presented here, B 0 s → φ φ and B 0 s → K * 0 K * 0 . These studies have been performed using, respectively, 1 f b −1 and 35pb −1 of data collected by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. In B 0 s → φ φ decay, the CP-violating phase arising in the interference between B 0 s -B 0 s mixing and the b → sss penguin decay has been determined to be in the interval [−2.46, −0.76] rad at 68% confidence level. The first observation of B 0 s → K * 0 K * 0 decay is also reported. The branching fraction and the CP-averaged K * 0 longitudinal polarization fraction are measured to be B(B 0 s → K * 0 K * 0 ) = (2.81 ± 0.46(stat.) ± 0.45(syst.) ± 0.34( f s / f d ))×10 −5 and f L = 0.31 ± 0.12(stat.) ± 0.04(syst.).