Dispersion relation for hadronic light-by-light scattering: subleading contributions
Year: 2025
Type: article
Abstract: A bstract In this work, we present an evaluation of subleading effects in the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. Using a recently derived optimized basis, we first study the matching of axial-vector contributions to short-distance constraints at the level of the scalar basis functions, finding that also the tails of the pseudoscalar poles and tensor mesons play a role. We then develop a matching strategy that allows for a combined evaluation of axial-vector and short-distance constraints, supplemented by an estimate of tensor-meson contributions based on simplified assumptions for their transition form factors. Uncertainties are primarily propagated from the axial-vector transition form factors and the variation of the matching scale, but we also consider estimates of the low-energy effect of hadronic states not explicitly included. In total, we obtain $$ {\left.{a}_{\mu}^{\textrm{HLbL}}\right|}_{\textrm{subleading}} $$ a μ HLbL subleading = 33 . 2(7 . 2) × 10 −11 , which in combination with previously evaluated contributions in the dispersive approach leads to $$ {\left.{a}_{\mu}^{\textrm{HLbL}}\right|}_{\textrm{total}} $$ a μ HLbL total = 101 . 9(7 . 9) × 10 −11 .
Source: Journal of High Energy Physics
Institutions: University of Bern, University of Zurich, Paul Scherrer Institute
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4407902985