Author/Authors :
OPAL Collaboration، نويسنده , , G. Alexander، نويسنده , , J. Allison، نويسنده , , N. Altekamp، نويسنده , , K. Ametewee، نويسنده , , K.J. Anderson، نويسنده , , S. Anderson، نويسنده , , S. Arcelli، نويسنده , , S. Asai، نويسنده , , D. Axen، نويسنده , , G. Azuelos، نويسنده , , A.H. Ball، نويسنده , , E. Barberio، نويسنده , , R.J. Barlow، نويسنده , , R. Bartoldus، نويسنده , , J.R. Batley، نويسنده , , J. Bechtluft، نويسنده , , C. Beeston، نويسنده , , T. Behnke، نويسنده , , A.N. Bell، نويسنده , , et al.، نويسنده ,
Abstract :
We have searched for excited states of charged and neutral leptons, e∗, μ∗, τ∗ and ν∗, in e+e− collisions at s=130 using the OPAL detector at LEP. No evidence for their existence was found. With the most common coupling assumptions, the final states from excited lepton pair production include ℓ+ℓ−γγ and ℓ+ℓ−WW (with the subsequent decay of the virtual W bosons). From the analysis of these final states, 95% confidence level lower mass limits of 66.5 GeV for e∗, 66.8 GeV for μ∗, 65.3 GeV for τ∗, 66.2 GeV for νe∗, 66.5 GeV for νμ∗ and 64.7 GeV for ντ∗ are inferred. From the analysis of γγ final states with missing energy and using alternative coupling assignments which permit photonic ν∗ decays, a 95% confidence level lower mass limit of 65.0 GeV for each ν∗ flavour is inferred. From the analysis of the ℓ+ℓ−γ, acoplanar lepton pair, and single γ final states expected from excited lepton single production, upper limits on fΛ (ratio of the coupling to the compositeness scale) are determined for excited lepton masses up to the kinematic limit.
