The ATLAS detector at the Large Hadron Collider is used to search for the lepton flavor violating process Z → eμ in pp collisions using 20.3 fb-1 of data collected at √s = 8 TeV. An enhancement in the eμ invariant mass spectrum is searched for at the Z-boson mass. The number of Z bosons produced in the data sample is estimated using events of similar topology, Z → ee and μμ, significantly reducing the systematic uncertainty in the measurement. There is no evidence of an enhancement at the Z-boson mass, resulting in an upper limit on the branching fraction, B(Z → 7.5 × 10.7 at the 95% confidence level.

Aad, G., Abbott, B., Abdallah, J., Abdel Khalek, S., Abdinov, O., Aben, R., et al. (2014). Search for the lepton flavor violating decay Z → eμ in pp collisions at √s = 8 TeV with the ATLAS detector. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 90(7), 1-19 [10.1103/PhysRevD.90.072010].

Search for the lepton flavor violating decay Z → eμ in pp collisions at √s = 8 TeV with the ATLAS detector

V. Bortolotto;F. Ceradini;B. Di Micco;R. Di Nardo;D. Orestano;