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 $h^0(H^0)\wt{f}_R^*\wt{f}_L$ rather than chirality conserving couplings.