Search for excited leptons in e+e− annihilation at s = 130-140 GeV

We report on a search for the excited leptons e∗, μ∗, τ∗ and ν∗ in e+e− collisions at s = 130-140 GeV using the L3 detector at LEP. No evidence has been found for their existence. From an analysis of the expected pair produced ℓ∗ℓ∗ in the channels eeγγ, μμγγ, ττγγ, eeWW, and ννγγ, we determine the lower mass limits at 95% C.L. of 64.7 GeV for e∗, 64.9 GeV for μ∗, 64.2 GeV for τ∗, 57.3 GeV (eW decay mode) and 61.4 GeV (νγ decay mode) for ν∗. From an analysis of the expected singly produced ℓℓ∗ in the channels eeγ, μμγ, ττγ, νeW and ννγ, we determine upper limits on the couplings λmℓ∗ up to mℓ∗ = 130 GeV.