Two-loop Barr-Zee type Contributions to $(g-2{)}_{\mu }$ in the MSSM

Abstract

We consider the contribution of a two-loop Barr-Zee type diagram to $(g-2{)}_{\mu }$ in the minimal supersymmetric standard model (MSSM). At relatively large $\tan \beta$, we show that the contribution of light third generation scalar fermions and neutral CP-even Higgs, $h^0(H^0)$, can easily explain the very recent BNL experimental data. In our analysis $(g-2{)}_{\mu }$ prefers negative $A_f$ and positive $\mu$. It is more sensitive to the chirality flipping $h^0(H^0)\text{wt}{f}_R^{\ast }\text{wt}{f}_L$ rather than chirality conserving couplings.

Comments: 10 pages, 5 figures, references added