Search for pair produced stable singly charged heavy particles in Z 0 decays
Abstract
A direct search for the exclusive pair production of stable singly charged heavy (SCH) particles in Z 0 decays at the LEP e +e - collider is presented. In a scan around the Z 0 resonance of 0.4 pb - integrated luminosity, no evidence is seen for the production of slow-moving charged particles as measured by their time-of-flight. We set an upper limit of 1 × 10 -3 on the Z 0 branching ratio into a pair of SCH fermions in the mass range 29-40 GeV/ c2, corresponding to a 3 MeV upper limit on such a contribution to the total width of the Z 0. We exclude a fourth generation SCH lepton in the mass range 18.5-42.8 GeV/ c2. We also exclude a stable supersymmetric partner of the right-handed lepton, l∼R, in the mass range 21.5-38.8 GeV/ c2. All limits are at 95% confidence level.
- Publication:
-
Physics Letters B
- Pub Date:
- December 1990
- DOI:
- 10.1016/0370-2693(90)90875-7
- Bibcode:
- 1990PhLB..252..290A