Effective lifetime measurements in the B-s(0) -> K+K-, B-0 -> K+pi(-) and B-s(0) -> pi K-+(-) decays

Abstract

Measurements of the effective lifetimes in the B0 s → K+K−, B0 → K+π − and B0 s → π +K− decays are presented using 1.0 fb−1 of pp collision data collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The analysis uses a datadriven approach to correct for the decay time acceptance. The measured effective lifetimes are τB0 s→K+K− = 1.407 ± 0.016 (stat) ± 0.007 (syst) ps, τB0→K+π− = 1.524 ± 0.011 (stat) ± 0.004 (syst) ps, τB0 s→π+K− = 1.60 ± 0.06 (stat) ± 0.01 (syst) ps. This is the most precise determination to date of the effective lifetime in the B0 s → K+K− decay and provides constraints on contributions from physics beyond the Standard Model to the B0 s mixing phase and the width difference ∆Γs