THE DECAY B-]S-GAMMA IN THE MSSM REVISITED

We present a re-analysis of the decay b --> sgamma in the Minimal Supe rsymmetric Standard Model with radiatively induced breaking of the gau ge group SU(2) x U(1). We extend this analysis to regions of the super symmetric parameter space wider than those previously studied. Results are explicitly presented for m(t) = 150 GeV. We discuss the consequen ces of a measurement of this decay at the Standard Model level for fut ure searches of charged Higgs and charginos. In spite of the strong se nsitivity of this decay to the effects of supersymmetry, we find that, at the moment, no lower limit on the mass of these particles can be o btained. The large chargino contribution to the branching ratio for b --> sgamma obtained at large values of tanbeta is effectively reduced by pushing the lightest eigenvalue of the up-squark mass matrix closer to the electroweak scale, i.e. by increasing the degree of degeneracy among the up-squarks.