Mixing and CP violation in D 0 → K − π + decays

We review the experimental methods to measure mixing and time-dependent CP violation in D 0 decays into two hadrons. While these phenomena are usually neglected for D 0 → K − π + decays, this approximation is not always justified. In particular, it produces a bias on the measurement of the parameter y CP , when this is performed by relying on D 0 → K − π + decays as a normalisation channel, whose size is around 40