{"paper":{"title":"Hard-Region Fermion Self-Energy and Fermion--Photon Vertex in Thermal QED through Two Loops","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ph","authors_text":"Ali Hataei","submitted_at":"2026-06-25T15:12:17Z","abstract_excerpt":"In massless thermal QED in a general covariant $R_\\xi$ gauge, we compute hard-region contributions to the fermion self-energy and the off-shell fermion--photon vertex at one-loop next-to-leading power and two-loop leading power in the soft-momentum expansion. The zero-temperature counterterms are also included to renormalize these hard amplitudes. Chiral invariance restricts the off-shell two-fermion--$N$-photon vertex to vector ($\\gamma_\\mu$) and axial-vector ($\\gamma_\\mu\\gamma_5$) Dirac structures. The vector part is constrained by the Ward--Takahashi identity (WTI), while the axial part is "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.27137","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2606.27137/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}