Lower limit on the mass of the neutralino (LSP) at LEP with the ALEPH detector

The large amount of data accumulated at LEP2 by the ALEPH experiment has been used to search for supersymmetric particles. No signal has been found therefore limits have been determined. Within the Constrained Minimal Supersymmetric Standard Model, the constraints from direct SUSY searches of charginos, sleptons and neutralinos, are combined to extract a lower limit on the mass of the neutralino considered to be the Lightest Supersymmetric particle. An improved limit is obtained when the limit on the Higgs mass is included. Neutralino masses up to 38 GeV/c^2 are excluded at 95 % confidence level.