The hadronic light-by-light contribution to the muon anomalous magnetic moment using twisted-mass lattice QCD
Nikolaos Kalntis · Open Access CRIS of the University of Bern · 2026
This thesis presents a lattice-QCD determination of the hadronic light-by-light (HLbL) contribution to the muon anomalous magnetic moment based on Nf = 2+1+1 Wilson-clover twisted-mass ensembles at the physical point, produced by the Extended Twisted Mass Collaboration (ETMC). Continuum-limit results are obtained for the strange- and charm-quark connected contributions through controlled extrapolations, including an assessment of both statistical and systematic uncertainties. For the light-quark connected and leading (2+2) disconnected contributions, results are presented at a single lattice spacing, incorporating all relevant statistical and systematic uncertainties. In addition, preliminary results from initial investigations at a finer lattice spacing are reported. These results constitute a significant step toward a fully controlled continuum-limit determination of the HLbL contribution within the twisted-mass formulation.