Study of CP violation and CPT violation in K*(892)→KS,L0π decays at BESIII

Abstract

The decays ${K}^{*}(892)\ensuremath{\rightarrow}{K}_{S,L}^{0}\ensuremath{\pi}$ can be used to study $CP$ violation and $CPT$ violation. The ${K}^{*}(892)$ (hereinafter referred to as ${K}^{*}$) meson can be produced via $J/\ensuremath{\psi}$ decays at BESIII. In this paper, we study $CP$ violation and ${K}_{S}^{0}\ensuremath{-}{K}_{L}^{0}$ asymmetry in the $J/\ensuremath{\psi}$ decays involving the ${K}^{*}$ meson in the final states and obtain the following results: ${\mathcal{A}}_{CP}(J/\ensuremath{\psi}\ensuremath{\rightarrow}{K}^{*}{f}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}{K}_{S}^{0}\ensuremath{\pi}{f}_{J/\ensuremath{\psi}})=(3.64\ifmmode\pm\else\textpm\fi{}0.04)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, ${\mathcal{A}}_{CP}(J/\ensuremath{\psi}\ensuremath{\rightarrow}{K}^{*}{f}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}\phantom{\rule{0ex}{0ex}}{K}_{L}^{0}\ensuremath{\pi}{f}_{J/\ensuremath{\psi}})=(\ensuremath{-}3.32\ifmmode\pm\else\textpm\fi{}0.04)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, and $R(J/\ensuremath{\psi}\ensuremath{\rightarrow}{K}^{*}{f}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}{K}_{S,L}^{0}\ensuremath{\pi}{f}_{J/\ensuremath{\psi}})=(3.51\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, $R(J/\ensuremath{\psi}\ensuremath{\rightarrow}{\overline{K}}^{*}{\overline{f}}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}{K}_{S,L}^{0}\ensuremath{\pi}{\overline{f}}_{J/\ensuremath{\psi}})=(\ensuremath{-}3.45\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. Based on two cases, the samples of ${10}^{10}$ and ${10}^{12}\text{ }\text{ }J/\ensuremath{\psi}$ events, we calculate the expected numbers of the observed signal events on the $CP$ violation and the ${K}_{S}^{0}\ensuremath{-}{K}_{L}^{0}$ asymmetry in the $J/\ensuremath{\psi}$ decays with ${K}^{*}$ meson in the final states, and we find that the BESIII experiment may be able to unambiguously observe $CP$ violation and ${K}_{S}^{0}\ensuremath{-}{K}_{L}^{0}$ asymmetry for each of these two cases. We study the possibility to constrain the $CPT$ violation parameter $z$ and discuss the sensitivity for the measurement of $z$ in $J/\ensuremath{\psi}$ decays with ${K}^{*}$ meson in the final states at BESIII. The sensitivity of the measurement of $z$ depends on the measured precision of the parameters ${m}_{L}\ensuremath{-}{m}_{S}$, ${\mathrm{\ensuremath{\Gamma}}}_{L}$, ${\mathrm{\ensuremath{\Gamma}}}_{S}$, $p$, and $q$ and the consistence between the values of ${t}_{0}$ and ${t}_{1}$ and the event selection criteria in experiment.