ONE-LOOP MSSM CONTRIBUTION TO THE WEAK MAGNETIC DIPOLE-MOMENTS OF HEAVY FERMIONS

The MSSM predictions at the one-loop level for the weak-magnetic dipol e moments of the tau lepton and the b quark are analysed, The entire s upersymmetric parameter space is scanned with the usual GUT constraint and common squark and slepton mass parameters. The real part of a(tau )(W) is dominated by the chargino contribution, being the same order a s the SM one or even larger in the high tan beta region whereas the im aginary part, due to Higgs boson diagrams, is negligible compared to t he SM value. The real part of a(b)(W) is controlled mainly by chargino s and also by gluinos, when the mixing in the bottom squark sector is large, to yield, for high tan beta, a contribution one order of magnit ude larger than the pure electroweak SM value but a factor five smalle r than the standard QCD contribution. The imaginary part of a(b)(W) is the same order as in the SM. (C) 1998 Elsevier Science B.V.