Search for Excited Leptons at LEP

TL;DR

This study searches for excited leptons in electron-positron collision data from LEP, finding no evidence but setting improved limits on their masses and couplings through combined analysis.

Contribution

First comprehensive search for excited leptons at LEP energies, providing new constraints on their properties by combining multiple production channels and previous results.

Findings

No signals detected for excited leptons.

Improved mass and coupling limits established.

Combined analysis enhances sensitivity.

Abstract

A search for charged and neutral excited leptons is performed in 217 pb^-1 of e+e- collision data collected with the L3 detector at LEP at centre-of-mass energies from 202 GeV up to 209 GeV. The pair- and single-production mechanisms of excited electrons, muons and taus, as well as of excited electron-, muon- and tau-neutrinos,are investigated and no signals are detected. Combining with L3 results from searches at lower centre-of-mass energies, gives improved limits on the masses and couplings of excited leptons.