Limitation on the constant of heavy lepton radiative decay according to data of the e+e- → γ + γ reactions

The effect of a heavy lepton in an intermediate state on the differential and total cross sections of the e+e- → γγ reaction has been investigated in order to obtain information on heavy lepton radiative decay L → eγ. On the basis of experimental data on the reaction the limitations on the constant lambda of the decay L → eγ are obtained as functions of the heavy lepton mass. It turns out that the upper limit for lambda rapidly increases with the heavy lepton mass and at m > 1 GeV lambda2 > 0.1