The role of vector meson dominance and running masses in the hadronic contributions to the muon $g-2$

Abstract

We summarize our recent results for the quark loop part of the light-by-light scattering contribution as well as the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon. In particular we focus on the role played by the momentum dependence of the quark- and quark-photon vertex dressing functions. We give a detailed comparison of the Dyson-Schwinger description of this contribution to the corresponding picture emerging from hadronic models in particular the extended Nambu--Jona-Lasonio model (ENJL). We find that the details of the momentum dependence are important on a quantitative level. Especially the transverse parts of the quark-photon-vertex, which serve as a dynamical extension of simple vector meson dominance models, do not yield the large suppression of the light-by-light contribution found in the ENJL model if realistic dressings are taken into account.

Contribution to 'Quark Confinement and the Hadron Spectrum X, October 8-12, 2012, Munich, Germany'

References in corpus (10)

• Nucleon electromagnetic form factors from the covariant Faddeev equation
• Hadronic unquenching effects in the quark propagator
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• The hadronic light by light contribution to the $(g-2{)}_{\mu }$ with holographic models of QCD
• Pion pole light-by-light contribution to g-2 of the muon in a nonlocal chiral quark model
• The light-by-light contribution to the muon (g-2) from lightest pseudoscalar and scalar mesons within nonlocal chiral quark model
• The role of momentum dependent dressing functions and vector meson dominance in hadronic light-by-light contributions to the muon g-2
• A fresh look at hadronic light-by-light scattering in the muon g-2 with the Dyson-Schwinger approach
• Hadronic corrections to the muon anomalous magnetic moment from lattice QCD
• Baryon properties from the covariant Faddeev equation