Experimental Limits on the Production of Excited Leptons and Stable Heavy Leptons

The results are reported of a search for excited muons (${\mu }^{*}$) and electrons ($e^{*}$) and for a stable charged heavy lepton by measurements of the $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}\gamma$, ${\mu }^{+}{\mu }^{-}\gamma$, ${\mu }^{+}{\mu }^{-}\gamma \gamma$, and $\gamma \gamma$ final states. Excluded are large regions of the $\lambda$ (coupling constant), $M$ (mass) planes for spin-½ ${\mu }^{*}$ and $e^{*}$, and a new stable charged heavy lepton with mass < 14 GeV.