Search for excited leptons in e⁺e⁻ annihilation at √s = 161 GeV

Abstract

A search for excited leptons e∗, μ^∗, Τ^∗ and ν^∗_c ine⁺e⁻ collisions at √s = 161 GeV is performed using the 10.8 pb⁻¹ of data collected by the L3 detector at LEP. No evidence has been found for their existence. From an analysis of the expected ℓ∗ℓ∗ pair production in the channels eeγγ, μμγγ, ΤΤγγ, eeWW, and ννγγ, the lower mass limits at 95% C.L. are 79.7 GeV for e^∗, 79.9 GeV for μ∗, 79.3 GeV for Τ∗ and 71.2 GeV for View the MathML source assuming the same couplings as for standard leptons. From an analysis of the expected ℓℓ∗ single production in channels eeγ, μμγ, ΤΤγ, ν_eeW and ννγ, the upper limits on the couplings λ/mlℓ∗ up to mlℓ∗ = 161 are determined.