{"paper":{"title":"A lattice QCD study of pion-nucleon scattering in the Roper channel","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ph"],"primary_cat":"hep-lat","authors_text":"Christian B. Lang, Luka Leskovec, M. Padmanath, Sasa Prelovsek","submitted_at":"2018-06-06T18:05:27Z","abstract_excerpt":"We present a lattice QCD study of the puzzling positive-parity nucleon channel, where the Roper resonance $N^*(1440)$ resides in experiment. The study is based on an ensemble of gauge configurations with $N_f=2+1$ Wilson-clover fermions with a pion mass of $156$ MeV and lattice size $L=2.9$ fm. We use several $qqq$ interpolating fields combined with $N\\pi$ and $N\\sigma$ two-hadron operators in calculating the energy spectrum in the rest frame. Combining experimental $N\\pi$ phase shifts with elastic approximation and the L\\\"uscher formalism suggests in the spectrum an additional energy level ne"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1806.02363","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"}