20-27 July 2011
Alpes Congrès - Alpexpo
Europe/Paris timezone

D(s)+ decays and CPV/mixing at Belle

22 Jul 2011, 09:45
Oisans (Alpes Congrès - Alpexpo)


Alpes Congrès - Alpexpo

Parallel session talk Flavour Physics and Fundamental Symmetries Flavour Physics and Fundamental Symmetries


Dr Marko Staric (Jozef Stefan Institute)


We report a measurement of $D^0$ - $\bar D^0$ mixing in $D^{0} \to K_S^0 \pi^{+} \pi^{-}$ decays using a time-dependent Dalitz plot analysis. We will also present an updated measurement of the mixing parameter $y_{CP}$ in decays $D^0 \to K^+K^-$ and $D^0 \to \pi^+\pi^-$. We will present a measurement to search for $CP$ violation in charged $D$ meson decays by measuring the $CP$ violating asymmetry difference between Cabibbo-suppressed decays $D^+ \to K^+K^- \pi^+$ and Cabibbo- favored decays $D_s^+ \to K^+K^- \pi^+$ in a mass region of the $\phi$ resonance. We have searched for CP violation in the decays $D^0\rightarrow K^0_S P^ 0$ where $P^0$ denotes a neutral pseudo-scalar meson which is either a $\pi ^0$, $\eta$, or $\eta'$. No evidence of significant CP violation is observed. We report the most precise CP asymmetry measurement in the decay $D^0\rightarrow K^0_S\pi^0$ to date: $A_{CP}^{D^0\rightarrow K^0_S\pi^0} =(-0.28\pm0.19\pm0.10)%$. We also report the first measurements of CP asymmetries in the decays $D^0\rightarrow K^0_S\eta$ and $D^0\rightarrow K^0_S\eta'$: $A_{CP}^{D^0\rightarrow K^0_S\eta}=(+0.54\pm0.51\pm0.16)%$ and $A_{CP}^{D^0\rightarrow K^0_S\eta'}=(+0.98\pm0.67\pm0.14)%$, respectively. We report the first observations of the decay $D^+ \to K^+ \eta^{(')}$ and the search for the CP violation in the decay $D^+ \to \pi^+ \eta^{(') }$. The branching ratios with respect to their normalization modes and CP measurements will be presented. We report preliminary results on the time-integrated asymmetry of the decays $D^0$ and $\bar{D^0}$ to $\pi^+ \pi^- \pi^0$. Results of the Dalitz plot analysis of $A_{CP}$ for two approaches -- model dependent and model independent -- are presented. The results are obtained from a large data sample collected on the $\Upsilon(4S)$ and $\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^+ e^-$ collider.

Primary author

Dr Marko Staric (Jozef Stefan Institute)

Presentation Materials