CP Violation in $\tau$ Decays at SuperB \& Super-Belle Experiments -- like Finding Signs of Dark Matter

Abstract

BaBar has found $A_{\rm CP}(\tau^- \to \nu K_S\pi^- [\geq \pi^0]) = (-0.36 \pm 0.23 \pm 0.11)%$ with 2.8 $\sigma$ difference with SM prediction $A_{\rm CP}(\tau^- \to \nu K_S\pi^-) = (0.36 \pm 0.01)%$ based on $K^0 - \bar K^0$ oscillation. Four central points: (i) to establish both the `existence' of New Dynamics (ND) and its `features' in local CP asymmetries; (ii) to increase the number of final states to be probed; (iii) to emphasize correlations of CP violations between different final states; (iv) likewise for the correlations with $D^{\pm}$ final states. These measurements should be possible at SuperB & Belle II experiments.