Radiative corrections to neutralino and chargino masses in the minimal supersymmetric model

We determine the neutralino and chargino masses in the MSSM at one loop. We perform a Feynman diagram calculation in the on-shell renormalization scheme, including quark-squark and lepton-slepton loops. We find generically the corrections are of the order of 5%. For a 20 GeV neutralino the corrections can be as large as 20%. The corrections change the region of [mu], [ital M][sub 2], tan[beta] parameter space which is ruled out by CERN LEP data. We demonstrate that, e.g., for a given [mu] and tan[beta] the lower limit on the parameter [ital M][sub 2] can shift by 20 GeV.