Mixing and CP violation in D0 → K−π+ decays

Abstract

Abstract We review the experimental methods to measure mixing and time-dependent CP violation in D0 decays into two hadrons. While these phenomena are usually neglected for D0 → K−π+ decays, this approximation is not always justified. In particular, it produces a bias on the measurement of the parameter yCP, when this is performed by relying on D0 → K−π+ decays as a normalisation channel, whose size is around 40% of the precision of the current world average. Finally, we estimate the sensitivity to the weak mixing phases achievable by studying D0 → K−π+ and untagged D → K−π+ decays, where D stands for either of the D0 and $$ \overline{D} $$ D ¯ 0 mesons. Contrary to Cabibbo-suppressed D0 → h+h− decays, these decay channels allow to measure these phases without final-state dependent nuisance contributions from the decay amplitudes, but their sensitivity is lower by a factor of six.