Search for the Lepton Flavor Violating Decay Z → eμ in pp Collisions at √s = 8 TeV with the ATLAS Detector

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 → eμ) < 7.5 x 10⁻⁷ at the 95% confidence level.