Search for CP violation using $T$-odd correlations in $D^0 \to K^+ K^- \pi^+ \pi^-$ decays

TL;DR

This study searches for CP violation in $D^0$ decays to $K^+ K^- \pi^+ \pi^-$ using T-odd correlations, analyzing a large dataset from BaBar, and finds no significant CP violation within measurement uncertainties.

Contribution

First measurement of CP violation in $D^0 o K^+ K^- \pi^+ \pi^-$ decays using T-odd correlations with a large BaBar dataset.

Findings

Measured CP violation parameter ${ m A}_T$ consistent with zero.

No evidence of CP violation observed within uncertainties.

Results set constraints on CP violation in charm decays.

Abstract

We search for CP violation in a sample of $4.7\times10^4$ Cabibbo-suppressed $D^0 \to K^+ K^- \pi^+ \pi^-$ decays. We use 470{\rm fb}^{-1} of data recorded by the BaBar detector at the PEPII asymmetric-energy $e^+e^-$ storage rings running at center-of-mass energies near 10.6 GeV. CP violation is searched for in the difference between the $T$-odd asymmetries, obtained using triple product correlations, measured for $D^0$ and $\bar D^0$ decays. The measured CP violation parameter is ${\cal A}_T = (1.0 \pm 5.1_{\sta}\pm 4.4_{\sys}) \times 10^{-3}$.