P. Abreu et al., Search for scalar fermions and long-lived scalar leptons at centre-of-massenergies of 130 GeV to 172 GeV, EUR PHY J C, 6(3), 1999, pp. 385-401
Data taken by DELPHI during the 1995 and 1996 LEP runs have been used to se
arch for the supersymmetric partners of electron, muon and tau leptons and
of top and bottom quarks. The observations are in agreement with standard m
odel predictions. Limits are set on sfermion masses. Searches for long live
d scalar leptons from low scale supersymmetry breaking models exclude stau
masses below 55 GeV/c(2) at the 95% confidence level, irrespective of the g
ravitino mass.