Search for excited leptons in e(+)e(-) collisions at root s=130 and 136 GeV

We have searched for excited states of charged and neutral leptons, e*, mu*, tau* and nu*, in e(+)e(-) collisions at root s = 130 and 136 GeV using the OPAL detector at LEP. No evidence for their existence was found. With the most common coupling assumptions, the final states from excited lepton pair production include l(+)l(-)gamma gamma and l(+)l(-)WW (with the subsequent decay of the virtual W bosons), From the analysis of these final states, 95% confidence level lower mass limits of 66.5 GeV for e*, 66.8 GeV for mu*, 65.3 GeV for tau*, 66.2 GeV for nu(e)*, 66.5 GeV for nu(mu)* and 64.7 GeV for nu(tau)* are inferred. From the analysis of gamma gamma final states with missing energy and using alternative coupling assignments which permit photonic nu* decays, a 95% confidence level lower mass limit of 65.0 GeV for each nu* flavour is inferred. From the analysis of the l(+)l(-)gamma, acoplanar lepton pair, and single gamma final states expected from excited lepton single production, upper limits on f/Lambda (ratio of the coupling to the compositeness scale) are determined for excited lepton masses up to the kinematic limit.