Effective lifetime measurements in the B0s→K+K−, B0→K+π− and B0s→π+K− decays

Measurements of the eective lifetimes in the B0 s ! K+K, B0 ! K+ and B0 s! +K decays are presented using 1:0 fb1 of pp collision data collected at a centre-of-mass energy of 7TeV by the LHCb experiment. The analysis uses a datadriven approach to correct for the decay time acceptance. The measured eective lifetimes are B0 s!K+K = 1:407 0:016 (stat) 0:007 (syst) ps; B0!K+ = 1:524 0:011 (stat) 0:004 (syst) ps; B0 s!+K = 1:60 0:06 (stat) 0:01 (syst) ps: This is the most precise determination to date of the eective 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 dierence s.