Search for CP Violation in the Decay D+/- -> Ks pi+/-

TL;DR

This paper reports a precise search for CP violation in D+/- decays to Ks pi+/- using a large data set, finding results consistent with the Standard Model and setting the most accurate measurement to date.

Contribution

The study provides the most precise measurement of CP violation in D+/- to Ks pi+/- decays, improving upon previous results with a large data sample.

Findings

Measured A_CP as (-0.44 ± 0.13 (stat) ± 0.10 (syst))%

Result is consistent with Standard Model prediction

Achieved the most precise measurement of this parameter to date

Abstract

We report on a search for CP violation in the decay $ D^\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 CPviolating decay rate asymmetry $A_{CP}$ is determined to be $(-0.44 \pm 0.13 \mathrm{(stat)} \pm 0.10 \mathrm{(syst)})%$, consistent with zero at 2.7 $\sigma$ and with the standard model prediction of $(-0.332 \pm 0.006)%$. This is currently the most precise measurement of this parameter.