{"paper":{"title":"Photoproduction of Etas and N$^*$(1535) Electrostrong Properties","license":"","headline":"","cross_cats":["hep-ph"],"primary_cat":"nucl-th","authors_text":"J. -F. Zhang, M. Benmerrouche, Nimai C. Mukhopadhyay","submitted_at":"1995-11-01T19:07:24Z","abstract_excerpt":"From the new Mainz data of eta photoproduction off protons\\cite{ref1} and deuterons\\cite{ref2}, we can extract, via the effective Lagrangian approach (ELA)\\cite{ref3}, the electrostrong parameters $\\xi_{p}$ and $\\xi_{n}$ for the N$^*$(1535) excitation. These parameters are, in units of $10^{-4} MeV^{-1}$, $(2.20\\pm 0.15)$ and $(-1.86\\pm 0.20)$ respectively. They yield the ratio of the helicity amplitudes for the excitation of N$^*$(1535) by photons off neutrons and protons to be $A^{n}_{1/2}/A^{p}_{1/2}=-0.84\\pm 0.15$, a quantity of fundamental importance in the baryon structure. Best estimate"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"nucl-th/9511001","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":""},"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"}