Measurements of charm mixing and C P violation using D0→K±π∓ decays

Abstract

Measurements of charm mixing and C P violation parameters from the decay-time-dependent ratio of D0→K+π- to D0→K-π+ decay rates and the charge-conjugate ratio are reported. The analysis uses B ¯ →D*+μ-X , and charge-conjugate decays, where D*+→D0π+ , and D0→K∓π± . The p p collision data are recorded by the LHCb experiment at center-of-mass energies √{s }=7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1 . The data are analyzed under three hypotheses: (i) mixing assuming C P symmetry, (ii) mixing assuming no direct C P violation in the Cabibbo-favored or doubly Cabibbo-suppressed decay amplitudes, and (iii) mixing allowing either direct C P violation and/or C P violation in the superpositions of flavor eigenstates defining the mass eigenstates. The data are also combined with those from a previous LHCb study of D0→K π decays from a disjoint set of D*+ candidates produced directly in p p collisions. In all cases, the data are consistent with the hypothesis of C P symmetry.