Search for CP violation in the Decays $D^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$, $D_s^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$, and $D_s^{\pm}\to K^0_{\scriptscriptstyle S} \pi^\pm$

TL;DR

This study searches for CP violation in specific D meson decays using a large data set, finding results consistent with the standard model and providing the most precise measurements to date.

Contribution

The paper presents the most precise measurements of CP asymmetries in D meson decays, using a large data set from the BABAR detector, and finds no evidence of CP violation.

Findings

Measured CP asymmetries are consistent with zero.

Results agree with standard model predictions.

Provides the most precise CP violation measurements in these decays.

Abstract

We report a search for CP violation in the decay modes $D^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$, $D_s^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$, and $D_s^{\pm}\to K^0_{\scriptscriptstyle S} \pi^\pm$ using a data set corresponding to an integrated luminosity of $469\,{\,fb}^{-1}$ collected with the {\slshape B\kern-0.1em{\smaller A}\kern-0.1em B\kern-0.1em{\smaller A\kern-0.2em R}} detector at the PEP-II asymmetric energy $e^+e^-$ storage rings. The decay rate CP asymmetries, $A_{CP}$, are determined to be $(+0.13 \pm 0.36 \stat \pm 0.25 \syst)%$, $(-0.05 \pm 0.23 \stat \pm 0.24 \syst)%$, and $(+0.6 \pm 2.0 \stat \pm 0.3 \syst)%$, respectively. These measurements are consistent with zero, and also with the standard model prediction ($(-0.332 \pm 0.006)%$ for the $D^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$ and $D_s^{\pm} \to K^0_{\scriptscriptstyle S} K^\pm$ modes, and $(+0.332 \pm 0.006)%$ for the $D_s^{\pm}\to K^0_{\scriptscriptstyle S} \pi^\pm$ mode). They are the most precise determinations to date.