{"paper":{"title":"Observable phi-eta-star at LHC and second-order QED matrix element in Z/gamma to l+ l- decays","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"hep-ph","authors_text":"Thi Kieu Oanh Doan, W.Placzek, Z. Was","submitted_at":"2013-03-09T15:30:26Z","abstract_excerpt":"In a recent publication by ATLAS collaboration a new observable, the so-called phi-star angle, was used for precise measurement of transverse Z momentum. One of the dominant systematic errors for this measurement originates from the theoretical control of QED final-state bremsstrahlung. At present, it is estimated at the 0.3% level for the shape of the phi-star distribution. In this paper we discuss the possible effects of the second-order QED matrix element for that quantity. For that purpose, results from simulations based on the Yennie--Frautchi--Suura (YFS) exponentiation and featuring the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1303.2220","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}