Charm CP violation and mixing at Belle

Abstract

We present charm CP violation and mixing measurements at Belle. They are the first observation of $D^0-\bar{D}^0$ mixing in $e^+e^-$ collisions from $D^0\rightarrow K^+\pi^-$ decays, the most precise mixing and indirect CP violation parameters from $D^0\rightarrow K^0_S\pi^+\pi^-$ decays, and the time-integrated CP asymmetries in $D^0\rightarrow\pi^0\pi^0$ and $D^0\rightarrow K^0_S\pi^0$ decays. Our mixing measurement in $D^0\rightarrow K^+\pi^-$ decays excludes the no-mixing hypothesis at the 5.1 standard deviation level. The mixing parameters $x=(0.56\pm0.19^{+0.03+0.06}_{-0.09-0.09})%$, $y=(0.30\pm0.15^{+0.04+0.03}_{-0.05-0.06})%$ and indirect CP violation parameters $|q/p|=(0.90^{+0.16+0.05+0.06}_{-0.15-0.04-0.05})$, arg$(q/p)=(-6\pm11\pm3^{+3}_{-4})^{\circ}$ measured from $D^0\rightarrow K^0_S\pi^+\pi^-$ decays, and the time-integrated CP asymmetries $A^{D^0\rightarrow\pi^0\pi^0}_{CP}=(-0.03\pm0.64\pm0.10)%$ and $A^{D^0\rightarrow K^0_S\pi^0}_{CP}=(-0.21\pm0.16\pm0.07)%$ are the most precise measurements to date. Our measurements here are consistent with predictions of the standard model.