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

DOI10.1093/PTEP/PTAA099zbMATH Open1477.81130arXiv2003.09834OpenAlexW3012905951MaRDI QIDQ5157601

Publication date: 19 October 2021

Published in: PTEP. Progress of Theoretical and Experimental Physics (Search for Journal in Brave)

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_{m} u^{2} / m_{Z}^{2}

. The results are compared with those obtained by the asymptotic expansion method.

Full work available at URL: https://arxiv.org/abs/2003.09834

Mathematics Subject Classification ID

Nuclear physics (81V35) Asymptotic approximations, asymptotic expansions (steepest descent, etc.) (41A60) Yang-Mills and other gauge theories in quantum field theory (81T13) Strong interaction, including quantum chromodynamics (81V05) Feynman diagrams (81T18) Anomalies in quantum field theory (81T50) Mono-, di- and multipole moments (EM and other), gyromagnetic relations (81V60)