Branching fraction and CP asymmetry of the decays B+→KS0π+ and B+→KS0K+

An analysis of B+→KS0π+ and B+→KS0K+ decays is performed with the LHCb experiment. The pp collision data used correspond to integrated luminosities of 1fb−1 and 2fb−1 collected at centre-of-mass energies of s=7TeV and s=8TeV, respectively. The ratio of branching fractions and the direct CP asymmetries are measured to be B(B+→KS0K+)/B(B+→KS0π+)=0.064±0.009 (stat.)±0.004(syst.), ACP(B+→KS0π+)=−0.022±0.025(stat.)±0.010 (syst.) and ACP(B+→KS0K+)=−0.21±0.14 (stat.)±0.01 (syst.). The data sample taken at s=7TeV is used to search for Bc+→KS0K+ decays and results in the upper limit (fc⋅B(Bc+→KS0K+))/(fu⋅B(B+→KS0π+))<5.8×10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a b¯ quark into a Bc+ or a B+ meson, respectively.