Search for T Violation in Charm Meson Decays

TL;DR

This study searches for T violation in charm meson decays using triple-product correlations in four-body decay channels, finding no evidence of T violation within experimental uncertainties.

Contribution

First measurement of T violation asymmetries in specific charm meson decays using triple-product correlations assuming CPT invariance.

Findings

Asymmetry values are consistent with zero within errors.

No evidence of T violation detected in analyzed decay modes.

Provides new measurements of CP asymmetries in charm decays.

Abstract

Using data from the FOCUS (E831) experiment, we have searched for T violation in charm meson decays using the four-body decay channels $D^0 \to K^-K^+\pi^-\pi^+$, $D^+ \to K^0_SK^+\pi^-\pi^+$, and $D^+_s \to K^0_SK^+\pi^-\pi^+$. The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. We find the asymmetry values to be $A_Tviol (D^0) = 0.010 \pm 0.057(stat.) \pm 0.037(syst.)$, $A_Tviol (D^+) = 0.023 \pm 0.062(stat.) \pm 0.022(syst.)$, and $A_Tviol (D^+_s) = -0.036 \pm 0.067(stat.) \pm 0.023(syst.)$. Each measurement is consistent with no T violation. New measurements of the CP asymmetries for some of these decay modes are also presented.