Charge-Parity violation in charm decays at Belle

Abstract

Using the full data sample collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we present CP violation in charm decays. The $D^0-\bar{D}^0$ mixing parameter $y_{CP}$ and indirect CP violation parameter $A_{\Gamma}$ in $D^0\rightarrow h^+h^-$ decays are reported, where $h$ denotes $K$ and $\pi$. The preliminary results are $y_{CP}=(1.11\pm0.22\pm0.11)%$ and $A_{\Gamma}=(-0.03\pm0.20\pm0.08)%$. We also report searches for CP violation in $D^0\rightarrow h^+h^-$ and $D^+\rightarrow K^0_S K^+$ decays. No evidence for CP violation in $D^0\rightarrow h^+h^-$ is observed with $A^{KK}_{CP}=(-0.32\pm0.21\pm0.09)%$ and $A^{\pi\pi}_{CP}=(+0.55\pm0.36\pm0.09)%$. The CP asymmetry difference between $D^0\rightarrow K^+K^-$ and $D^0\rightarrow\pi^+\pi^-$ decays is measured with $\Delta A^{hh}_{CP}=(-0.87\pm0.41\pm0.06)%$. The CP asymmetry in $D^+\rightarrow K^0_S K^+$ decay is measured to be $(-0.25\pm0.28\pm0.14)%$. After subtracting CP violation due to $K^0-\bar{K}^0$ mixing, the CP asymmetry in $D^+\rightarrow\bar{K}^0 K^+$ decay is found to be $(+0.08\pm0.28\pm0.14)%$.