Model-independent measurement of mixing parameters in D0 → K S 0 π+π− decays

The first model-independent measurement of the charm mixing parameters in the decay D 0 → K S 0 π + π − is reported, using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 1.0 fb−1 at a centre-of-mass energy of 7 TeV. The measured values are x=(−0.86±0.53±0.17)×10−2,y=(+0.03±0.46±0.13)×10−2, x=(−0.86±0.53±0.17)×10−2,y=(+0.03±0.46±0.13)×10−2, where the first uncertainties are statistical and include small contributions due to the external input for the strong phase measured by the CLEO collaboration, and the second uncertainties are systematic

Branching fraction and CP asymmetry of the decays B+ -> K-S(0)pi(+) and B+ -> (KSK+)-K-0

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=7 TeV is used to search for Bc+→KS0K+ decays and results in the upper limit (fc{dot operator}B(Bc+→KS0K+))/(fu{dot operator}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. © 2013 CERN