2026/07/23 by Matteo Di Carlo, Antonin Portelli
#hep-lat
In this paper we derive the expansion of the generalized domain-wall fermion Dirac operator including electromagnetic corrections up to O(e2), which are relevant for lattice computations of radiative corrections to hadronic processes with chiral fermions. In the generalized formulation of the domain-wall fermionic QCD+QED action, physical quark fields are related to the corresponding five-dimensional fields in a way which depends on the (QCD+QED) gauge links, generating extra contact terms when expanding correlation functions with respect to the electric charge. We re-derive the known first-order correction using a background-field approach and, at second order, obtain new local operator insertions (seagull vertices) required for gauge covariant calculations.