A DIRECT SEARCH FOR NEW CHARGED HEAVY LEPTONS AT LEP

This is the post-print version of the Article - Copyright @ 1990 ElsevierResults are presented from a search for a new charged heavy lepton in e+e− annihilation. The data were taken with the OPAL detector at LEP during a scan of the Z0 resonance. Two independent search techniques were used, one looking for events with large missing energy and missing momentum transverse to the beam, and the other for events with isolated energetic leptons. Two candidate events, consistent with expected background, were found in the first search; none was found in the second. These results allow the exclusion at the 95% confidence level of a charged heavy lepton of mass less than 44.3 GeV/c2 if it is assumed to have a massless neutrino partner. Limits are also presented for the case of a massive neutrino.This study is supported by The Bundesministerium f'tir Forschung und Technologie, FRG, The Department of Energy, USA, The Institut de Recherche Fondamentale du Commissariat a l'Energie Atomique, The Israeli Ministry of Science, The Minerva Gesellschaft, The National Science Foundation, USA, The Natural Sciences and Engineering Research Council, Canada, The Japanese Ministry of Education, Science and Culture (the Monbusho) and a grant under the Monbusho International Science Research Program, The Science and Engineering Research Council, UK and The A.P. Sloan Foundation