Key points are not available for this paper at this time.
Standard model loop contributions to the muon anomalous magnetic moment, a_ (g_-2) /2, and their theoretical uncertainties are scrutinized. The status and implications of the recently reported 2. 6 sigma experiment versus theory deviation a_^expt-a_^SM=426 (165) 10^-11 are discussed. Possible explanations due to supersymmetric loop effects with mₒₔₒₘ55-₈^+16tan GeV, radiative mass mechanisms at the 1--2 TeV scale and other ``new physics'' scenarios are examined.
Czarnecki et al. (Wed,) studied this question.