Hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon at the physical pion mass
Zoltan Fodor, Antoine Gérardin, Laurent Lellouch, Kalman K. Szabo, Balint C. Toth, Christian Zimmermann · Physical review. D/Physical review. D. · 2025
We present a lattice quantum chromodynamics (QCD) calculation of the hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon using N f = 2 + 1 + 1 flavors of staggered quarks with masses tuned to their physical values. Our final result, in the continuum limit, reads a μ hlbl = 125.5 ( 11.5 ) stat ( 1.9 ) syst × 10 − 11 where the first error is statistical and the second is systematic. Light, strange, and charm-quark contributions are considered. In addition to the connected and leading disconnected contributions, we also include an estimate of the subleading disconnected diagrams. Our result is compatible with previous lattice QCD and data-driven dispersive determinations.