Branching fraction and CP asymmetry of the decays B[superscript +] → K[subscript 0][superscript S]π[superscript +] and B[superscript +] → K[subscript 0][subscript S] K[supercript +] ✩

Abstract

An analysis of B[superscript +] →K[subscript S][superscript 0] π[superscript +] and B[superscript +] →K[subscript S][superscript 0] K[superscript +] decays is performed with the LHCb experiment. The pp collision data used correspond to integrated luminosities of 1fb[superscript -1] and 2fb[superscript -1] collected at centre-of-mass energies of √s=7 TeV and √s=8 TeV, respectively. The ratio of branching fractions and the direct CP asymmetries are measured to be B(B[superscript +] →K[subscript S][superscript 0]K[superscript +])/B(B[superscript +] →K[subscript S][superscript 0] π[superscript +])=0.064 ± 0.009 (stat.) ± 0.004(syst.), A[superscript CP] (B[superscript +] →K[subscript S][superscript 0]π[superscript +])=-0.022 ± 0.025(stat.) ± 0.010 (syst.) and A[superscript CP](B[superscript +] →K[subscript S][superscript 0] K[superscript +])=-0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at √s=7 TeV is used to search for B[subscript c][superscript +]→K[subscript S][superscript 0] K[superscript +] decays and results in the upper limit (f[subscript ] [dot]B(B[subscript c][superscript +] →K[suscript S][supercript 0] K[superscript +]))/(fu[dot]B(B[superscript +] →K[subscript S][superscript 0] π[superscript +])) < 5.8×10[superscript -2] at 90% confidence level, where f[subscript c] and f[subscript u] denote the hadronisation fractions of a b- quark into a B[superscript +][subscript c] or a B[superscript +] meson, respectively.