We analyze the anomalous magnetic moment of the muon a,, in supersymmetric scenarios. First we concentrate on scenarios with universal soft terms. We find that a moderate increase of a, can be obtained by lowering the unification scale M-GUT to intermediate values of 10(10) to 10(12) GeV. However, large values of tan beta are still favored. Then we study the case of nonuniversal soft terms. For the usual value M-GUT approximate to 10(16) GeV. we obtain alpha (mu) in the favored experimental range even for moderate tan beta regions (tan beta greater than or similar to 5). Finally, we give an explicit example of these scenarios. In particular, we show that in a D-brane model, wre the string scale is naturally of the order of 10(10) to 10(12) GeV and the soft terms are nonuniversal. alpha (mu) is enhanced with low tan beta.
