Measurement of indirect CP-violating asymmetries in D0 K+K− and D0 π+ π− decays at CDF

Abstract

We report a measurement of the indirect CP-violating asymmetries (AG) between effective lifetimes of anticharm and charm mesons reconstructed in D0?K+K- and D0?p+p- decays. We use the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab experiment and corresponding to 9.7??fb-1 of integrated luminosity. The strong-interaction decay D*+?D0p+ is used to identify the meson at production as D0 or ¯D0. We statistically subtract D0 and ¯D0 mesons originating from b-hadron decays and measure the yield asymmetry between anticharm and charm decays as a function of decay time. We measure AG(K+K-)=(-0.19±0.15(stat)±0.04(syst))% and AG(p+p-)=(-0.01±0.18(stat)±0.03(syst))%. The results are consistent with the hypothesis of CP symmetry and their combination yields AG=(-0.12±0.12)%.