Radiative decays of leptons in the supersymmetric standard model

We study radiative decays of charged leptons {ital l}{sub {ital i}}{r arrow}{ital l}{sub {ital j}}{gamma}({gamma}*) within the framework of the supersymmetric generalization of the standard model. We write out form factors for the one-loop vertex function in their most general form. We calculate the widths for the indicated decays. For maximal values of the mixing angles in the scalar sector we estimate the masses of the scalar leptons on the basis of the available upper limit on the {mu}{r arrow}{ital e}{gamma} branching ratio. For maximum mixing angle and least degeneracy of the masses of scalar leptons from different generations we obtain the following lower bound on the mass of the scalar electron: {ital m}{sub {ital {tilde e}}}{gt}1.5 TeV. The scalar-neutrino mass is {le}{ital O}(1) GeV. The scalar neutrinos could also be heavy ({ge}{ital O}(1)TeV) if the charged gauginos are lighter than the scalar neutrinos. These results are sensitive to the choice of the lepton mixing angle in the scalar sector: a decrease of sin 2{theta} by an order of magnitude can lower the bound on the mass of the scalar electron by more than a factor of three. In the latter case direct observation of scalar electrons at the Serpukhovmore » {ital e}{sup +}{ital e}{sup {minus}} collider (1{times}1 TeV) becomes possible.« less