  Searches for pair production of squarks, sleptons, charginos, and neutralinos
are performed with the data collected by the ALEPH detector at LEP at
centre-of-mass energies from 188.6 to 201.6 GeV. No evidence for any such
signals is observed in a total integrated luminosity of about 410pb-1. The
negative results of the searches are translated into exclusion domains in the
space of the relevant MSSM parameters, which improve significantly on the
constraints set previously. Under the assumptions of gaugino and sfermion mass
unification, these results allow a 95% C.L. lower limit of 37GeV/c2 to be set
on the mass of the lightest neutralino for any tan beta and sfermion mass.
Additional constraints in the MSSM parameter space are derived from the
negative results of ALEPH searches for Higgs bosons. The results are also
interpreted in the framework of minimal supergravity.
