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, ${\mathit{M}}_2$, tanβ parameter space which is ruled out by CERN LEP data. We demonstrate that, e.g., for a given μ and tanβ the lower limit on the parameter ${\mathit{M}}_2$ can shift by 20 GeV.

• Received 9 December 1993

DOI:https://doi.org/10.1103/PhysRevD.50.565