We have searched for excited states of charged and neutral leptons, e*, μ*, τ* and ν*, in e+e- collisions at √s = 161 GeV using the OPAL detector at LEP. No evidence for their existence was found. With the most common coupling assumptions, the topologies from excited lepton pair production include ℓ+ℓ-γγ and ℓ+ℓ-W+W-, with the subsequent decay of the virtual W bosons. From the analysis of these topologies, 95% confidence level lower mass limits of 79.9 GeV for e*, 80.0 GeV for μ*, 79.1 GeV for τ*, 78.3 GeV for ν*e, 78.9 GeV for ν*μ and 76.2 GeV for ν*τ are inferred. From the analysis of W+W- and γγ topologies with missing energy and using alternative coupling assignments which favour charged ℓ*± and photonic ν* decays, 95% confidence level lower mass limits of 77.1 GeV for each ℓ*± flavour and 77.8 GeV for each ν* flavour are inferred. From the analysis of the ℓ+ℓ-γ, ℓ±W∓ and single γ final states expected from excited lepton single production, upper limits on the ratio of the coupling to the compositeness scale, f/Λ, are determined for excited lepton masses up to the kinematic limit.
|Number of pages||13|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - 9 Jan 1997|
ASJC Scopus subject areas
- Nuclear and High Energy Physics