A search for the charged-lepton-flavor-violating process Z -> e mu is presented, using 139 fb(-1) of root s = 13 TeV pp collision data collected by the ATLAS experiment at the LHC. An excess in the e mu invariant mass spectrum near the Z boson mass would be a striking signature of new physics. No excess is observed, and an upper limit B(Z -> e mu) < 2.62 x 10(-7) is placed on the branching fraction at 95% confidence level, which is the most stringent limit to date.

Aad, G., Abbott, B., Abbott, D. ., Abed Abud, A., Abeling, K., Abhayasinghe, D. ., et al. (2023). Search for the charged-lepton-flavor-violating decay Z → eμ in pp collisions at √s=13 TeV with the ATLAS detector. PHYSICAL REVIEW D, 108(3) [10.1103/PhysRevD.108.032015].

Search for the charged-lepton-flavor-violating decay Z → eμ in pp collisions at √s=13 TeV with the ATLAS detector

I. Bashta;V. D'Amico;B. Di Micco;R. Di Nardo;D. Orestano;F. Petrucci;