B Meson Decays

Observation of the decay B + → ψ(2S)φ(1020)K + in pp collisions at √ s = 8 TeV .The CMS Collaboration CERN, Switzerland The decay B + → ψ(2S)φ(1020)K + is observed for the first time using data collected from pp collisions at √ s = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb −1. The branching fraction of this decay is measured, using the mode B + → ψ(2S)K + as normalization, to be (4.0 ± 0.4 (stat) ± 0.6 (syst) ± 0.2 (B)) × 10 −6 , where the third uncertainty is from the measured branching fraction of the normalization channel.

Abstract: The decay constants of the pseudoscalar mesons B and Bs are evaluated from QCD sum rules for the pseudoscalar two-point function. Recently calculated perturbative three-loop QCD corrections are incorporated into the sum rule. An analysis in terms of the bottom quark pole mass turns out to be unreliable due to large higher order corrections. On the contrary, in the MS scheme the radiative corrections are under good theoretical control and a reliable determination of fB and fBs becomes feasible. Including variations of all input parameters within reasonable ranges, our final results for the pseudoscalar meson decay constants are fB = 197±23 MeV and fBs = 232±25 MeV. Employing additional information on the product √ BBfB from global fits to the unitarity triangle, we are in a position to also extract the B-meson B-parameter BB = 1.25 ± 0.41. Our results are very compatible with analogous determinations of the above quantities in lattice QCD, albeit with smaller errors in the ...