Search for the lepton number violation decay ω→π ⁺ π ⁺ e ⁻ e ⁻+c.c.*

This is the authors' abstract. We don't add key points for this paper.

Lepton number violation decay is searched for via using a data sample of events collected via the BESIII detector at the BEPCII collider. No significant signal is observed, and the upper limit on the branching fraction of at the 90% confidence level is determined for the first time to be .