Search for chargino pair production in scenarios with gravitino LSP and stau NLSP at root s similar to 183 GeV at LEP

Promptly decaying lightest charginos were searched for in the context of scenarios with gravitino LSP. It was assumed that the stau is the next to lightest supersymmetric particle (NLSP). Data collected with the DELPHI detector at a centre-of-mass energy near 183 GeV were analysed combining the methods developed in previous searches. No evidence for the production of these particles was found. Hence, limits were derived at 95% confidence level. The mass of charginos was found to be greater than 85.5 GeV/c(2) for m(<(chi)over bar>1+) -m(<(tau)over bar>1) greater than or equal to 0.3 GeV/c(2), independently of the mass of the gravitino. (C) 1999 Published by Elsevier Science B.V. AU rights reserved.