Electroweak fermion triangle loop contributions to the muon anomalous magnetic moment revisited

Abstract

The contribution to the muon anomalous magnetic moment from the fermion triangle loop diagrams connected to the muon line by a photon and a $Z$ boson is reanalyzed in the unitary gauge. With use of the anomalous axial-vector Ward identity, it is shown that the calculation in the unitary gauge exactly coincides with the one in the 't Hooft-Feynman gauge. The part which arises from the ordinary axial-vector Ward identity corresponds to the contribution of the neutral Goldstone boson. For the top-quark contribution, the one-parameter integral form is obtained up to the order of $m_{\mu }^2/m_Z^2$. The results are compared with those obtained by the asymptotic expansion method.

5 pages, 2 figures (a) and (b)

References in corpus (4)

• JaxoDraw: A graphical user interface for drawing Feynman diagrams
• Refinements in electroweak contributions to the muon anomalous magnetic moment
• Numerical calculation of the full two-loop electroweak corrections to muon (g-2)
• Top-quark loops and the muon anomalous magnetic moment