Search for the charged lepton flavor violating decay J/ψ → eτ

A search for the charged lepton flavor violating decay J/psi -> e(+/-)tau(-/+) with tau(-/+) -> pi(-/+)pi(0)nu(tau) is performed with about 10 x 10(9) J/psi events collected with the BESIII detector at the BEPCII. No significant signal is observed, and an upper limit is set on the branching fraction B(J/psi -> e(+/-)tau(-/+)() <) 7.5 x 10(-8) at the 90% confidence level. This improves the previously published limit by two orders of magnitude.

Automated summary

By analyzing approximately 10 x 10(9) J/psi events collected at the BEPCII with the BESIII detector, a search for the charged lepton flavor violating decay J/psi -> e(+/-)tau(-/+) with tau(-/+) -> pi(-/+)pi(0)nu(tau) was conducted. No significant signal was observed, leading to an upper limit set on the branching fraction B(J/psi -> e(+/-)tau(-/+)() <) 7.5 x 10(-8) at the 90% confidence level, which represents an improvement by two orders of magnitude compared to the previously published limit.