Search for the charmonium weak decay $J/\psi\to\bar{D}^0\bar{K}^{*0}+{\rm c.c.}$

TL;DR

This study searches for a rare weak decay of the J/psi particle into specific mesons using a large data sample, setting a new upper limit on its branching fraction.

Contribution

The paper provides the most sensitive upper limit to date on the branching fraction of the rare decay J/psi to anti-D0 and anti-K*0 mesons.

Findings

No significant signal observed for the decay.

Upper limit on branching fraction set at 1.4×10⁻⁷.

Sensitivity improved by an order of magnitude over previous results.

Abstract

Based on a sample of $(10087\pm44)\times10^6$ $J/\psi$ events collected at the center-of-mass energy $\sqrt{s}$ = 3.0969 GeV with the BESIII detector, we search for the charmonium rare weak decay $J/\psi\to\bar{D}^0\bar{K}^{*0}+{\rm c.c.}$. No significant signal is observed, and the upper limit on its decay branching fraction at the 90% confidence level is set as $1.4\times10^{-7}$, improving the sensitivity of the previous best limit by an order of magnitude.