c -> u gamma in the minimal supersymmetric standard model

The minimal supersymmetric standard model (MSSM) with universal soft breaki ng terms has a negligible effect on the rare c --> u gamma decay rate. We t herefore study a general model with non-universal soft breaking terms const rained by vacuum stability and the experimental upper bound on the mass dif ference of the neutral charm mesons. It turns out that gluino exchange can enhance the standard model rate by up to two orders of magnitudes; in contr ast, the contributions from charginos and neutralinos remain at least an or der of magnitude below the QCD corrected standard model rate. (C) 2001 Publ ished by Elsevier Science B.V.