D^0 \to K^{\pm}\pi^{\mp} and CP Violation at a \tau-charm Factory

Abstract

We calculate the time-dependent and time-integrated decay rates of $(D^0{\bar{D}}^0)\to (K^{\pm }{\pi }^{\mp })(l^{\pm }{X}^{\mp })$ at the $\psi (3.77)$ and $\psi (4.14)$ resonances. The possibilities to distinguish between the effects of $D^0-{\bar{D}}^0$ mixing and doubly Cabibbo suppressed decay (DCSD) are illustrated, and the signal of $CP$ violation induced by the interplay of mixing and DCSD is discussed. Ratios of the decay rates of $(D^0{\bar{D}}^0)\to (K^{\pm }{\pi }^{\mp })(K^{\pm }{\pi }^{\mp })$ to that of $(D^0{\bar{D}}^0)\to (K^{+}{\pi }^{-})(K^{-}{\pi }^{+})$ are also recalculated by accommodating $CP$ violation and final-state interactions.

Comments: 13 pages. (Phys. Lett. B in press)