Search for supersymmetry with R-parity violating LL(E)over-bar couplings at root s=183 GeV

Searches for pair production of supersymmetric particles in e(+)e(-) collisions at centre-of-mass energy of 183 GeV have been performed on DELPHI data under the assumption that R-parity is not conserved. Only one R-parity violating coupling of lambda type, which couples the sleptons to the leptons (LL (E) over bar term), is considered to be dominant at a time. Since in models with R-parity violation any supersymmetric particle can be the lightest one, searches for charginos, neutralinos, sleptons and squarks have been performed both for direct R-parity violating decays and for indirect cascade decays. Morever, it is assumed that the strength of the R-parity violating couplings is such that the lifetimes can be neglected. The present study of supersymmetric particle pair production is used to exclude domains of the Minimal Supersymmetric Standard Model parameter space previously explored under the assumption of R-parity conservation.