$D^0 - \bar D^0$ mixing: A possible test of physics beyond the Standard Model

Abstract

It is shown that the$D^0 - \bar D^0$ mixing is strongly suppressed in the Standard Model and is smaller by several orders of magnitude than the current experimental upper-bound. The detection of a stronger$D^0 - \bar D^0$ mixing in the future experiments might indicate the existence of a new physics beyond the Standard Model. As an example, it is shown that in a class of simple super-symmetric theories$D^0 - \bar D^0$ mixing could be substantially larger than the Standard Model prediction. If on the other hand the Standard Model prediction is confirmed by future experiments that will require that the super-symmetric extension of the standard model should have a much larger SUSY breaking scale than that indicated by the phenomenology of the neutral kaon system.