Search for stable and long-lived massive charged particles in a(+)e(-) collisions at root s=130-209 GeV

摘要

A search for stable and long-lived massive particles of electric charge Q/e = 1 or fractional charges of 2/3, 4/3, and 5/3 is reported using data collected by the OPAL detector at LEP, at centre-of-mass energies from 130 to 209 GeV These particles are assumed to be pair-produced in e(+)e(-) collisions and not to interact strongly. No evidence for the production of these particles was observed. Model-independent upper limits on the production cross-section between 0.005 and 0.028 pb have been derived for scalar and spin-1/2 particles with charge +/-1. Within the framework of the Constrained Minimal Supersymmetric Standard Model (CMSSM), this implies a lower limit of 98.0 (98.5) GeV on the mass of long-lived right- (left-)handed scalar muons and scalar taus. Long-lived charged heavy leptons and charginos are excluded for masses below 102.0 GeV For particles with fractional charge +/-2/3, +/-4/3 and +/-5/3, the upper limit on the production cross-section varies between 0.005 and 0.020 pb. All mass and cross-section limits are derived at the 95% confidence level and are valid for particles with lifetimes longer than 10(-6) s. (C) 2003 Elsevier B.V. All rights reserved. [References: 49]