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 {μ}, M₂, tan{β} parameter space which is ruled out by CERN LEP data. We demonstrate that, e.g., for a given {μ} and tan{β} the lower limit on the parameter M₂ can shift by 20 GeV.