No-Scale Scenarios in the Light of New Measurement of Muon Anomalous Magnetic Moment

Abstract

Supersymmetric contribution to the muon anomalous magnetic moment a_μis discussed in the no-scale-type supersymmetry breaking scenarios. Taking the correlation between the supersymmetric contributions to a_μand Br(b\to sγ), it is shown that the precise measurements of these quantities serve an important constraint on the relative sign of the gaugino masses; combining the 2.6-σdeviation in a_μfrom the standard-model prediction measured by the E821 experiment and Br(b\to sγ) measured by CLEO, the sign of the product M_2M_3 is strongly preferred to be positive, where M_2 and M_3 are SU(2)_L and SU(3)_C gaugino mass parameters, respectively. In particular, no-scale-type models with universal gaugino masses are in accord with the two constraints and also with the Higgs mass bound. In addition, it is also shown that future improvements in the measurements of a_μand Br(b\to sγ) may provide serious test of the cases with M_2M_3<0.

10 pages, 4 figures, published version