A Note on One Loop Electroweak Contributions to g-2: a Companion to BUHEP-01-16

In this note we present general expressions at one loop order that can be used to calculate the contributions to the anomalous magnetic moment of fundamental, charged Dirac fermions. In particular, we provide the expressions for charged and neutral scalar and charged and neutral gauge boson contributions with general vector and axial couplings to the fermion of interest. The calculations presented in this note were originally derived for use in the author’s letter, hep-ph/0108080. We have chosen to document and make available the results and derivations in the hope that they will also be useful to others. Our expressions reproduce the Standard Model electroweak contributions to a_muon in the appropriate mass limits, and are flexible enough to allow us to handle many scenarios of new physics beyond the Standard Model.