Search for Excited Leptons using the ALEPH detector at LEP

Radiative decays of excited leptons were searched for in all data collected by ALEPH up to $188.6\gev$. No evidence for a signal was found. Excited states were excluded at 95\% confidence level for masses close to 94.3 GeV$/c^2$ for $e^*$, $\mu^*$, and $\tau^*$ and $\nu^*$. For single production when $f=f^\prime$, the 95\% C.L. exclusion limits on the couplings, $\frac{|f|}{\Lambda}$, for an excited lepton mass of 150 GeV$/c^2$ are close to 0.2 TeV$^{-1}$ for $e^*$ and 2 TeV$^{-1}$ for $\mu^*$, $\tau^*$. For a $\nu^*$ mass of 150 GeV$/c^2$ the limit is 3 TeV$^{-1}$ when $f=-f^\prime$.