Measurement of mixing and CP violation parameters in two-body charm decays
A study of mixing and indirect CP violation in D-0 mesons through the determination of the parameters y(CP) and A(Gamma) is presented. The parameter y(CP) is the deviation from unity of the ratio of effective lifetimes measured in D-0 decays to the CP eigenstate K+K- with respect to decays to the Cabibbo favoured mode K-pi(+). The result measured using data collected by LHCb in 2010, corresponding to an integrated luminosity of 29 pb(-1), is y(CP) = (5.5 +/- 6.3(stat) +/- 4.1(syst)) x 10(-3). The parameter A(Gamma) is the asymmetry of effective lifetimes measured in decays of D-0 and (D) over bar (0) mesons to K+K-. The result is A = (-5.9 +/- 5.9(stat) +/- 2.1(syst)) x 10(-3). A data-driven technique is used to correct for lifetime-biasing effects.