A fresh look at hadronic light-by-light scattering in the muon g-2 with the Dyson-Schwinger approach

Abstract

We present first results for the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon a_μ in the framework of Dyson-Schwinger and Bethe-Salpeter equations. We determine the quark loop and pseudoscalar (π^0, η, η') meson exchange diagram using a phenomenological model for the combined strength of the gluon propagator and the quark-gluon interaction as the only input. Our result for meson exchange, a_μ^{LBL;PS}=(84 \pm 13) x 10^{-11}, is commensurate with previous calculations. However, our number for the quark loop contribution, a_μ^{LBL;quarkloop} = (107 \pm 2 \pm 46) x 10^{-11}, is significantly larger due to dressing effects in the quark propagator and the quark-photon vertex. Taken at face value, this then leads to a revised estimate of the total a_μ=116 591 865.0(96.6) x 10^{-11}, which reduces the difference between theory and experiment to about 1.9 σ.

5 pages, 7 figures, v2: title slightly changed, minor corrections, version accepted by EPJ

References in corpus (6)

• Infrared Properties of QCD from Dyson-Schwinger equations
• Status of the Fermilab Muon (g-2) Experiment
• The Hadronic Light-by-Light Contribution to the Muon Anomalous Magnetic Moment: Where do we stand?
• Hadronic unquenching effects in the quark propagator
• Beyond the rainbow: effects from pion back-coupling
• Pion pole light-by-light contribution to g-2 of the muon in a nonlocal chiral quark model

Cited by in corpus (6)

• The pseudoscalar hadronic channel contribution of the light-by-light process to the muon (g-2) within the 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
• Pion light-by-light contributions to the muon $g-2$
• The role of momentum dependent dressing functions and vector meson dominance in hadronic light-by-light contributions to the muon g-2
• The muon g-2: retrospective and future
• The role of vector meson dominance and running masses in the hadronic contributions to the muon $g-2$