CP violation in charm decays at Belle

Abstract

We have searched for CP violation of charmed mesons in the decays $D\to K^0_S P$, where $D$ denotes $D^0$ and $D^+_{(s)}$, and $P$ denotes the pseudo-scalar mesons $\pi^+$, $K^+$, $\pi^0$, $\eta$, and $\eta'$. No evidence of CP violation in these decays is observed. We also have measured the CP asymmetry difference between the Cabibbo suppressed decay $D^+\to\phi\pi^+$ and the Cabibbo favored $D^+_s\to\phi\pi^+$ decays in the region of $|M(K^+K^-)-M^{\phi}_{PDG}|<$16 MeV/$c^2$. The measured asymmetry is corrected for the residual asymmetry due to detector effects, and the contributions of both CP and forward-backward asymmetries are determined. These results are obtained on a large data sample collected at and near the $\Upsilon(4S)$ resonance with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider.