Effect of Excited and Fourth Generation Leptons in Lepton Flavor Violating μ− → e−2γ Decay

We study the lepton flavor violating μ− → e−2γ decay induced by the mediation of heavy leptons, such as the excited and fourth generation leptons. Effects of these leptons in μ− → e−2γ decay are examined. It is found that the branching ratio of this decay is very sensitive to excited and fourth generation leptons. Furthermore, we obtain the bounds on model parameters by using the current experimental limit of this decay. (the physics of elementary particles and fields)