{"arxiv_id":"2010.01270","title":"The negative-parity spin-1/2 $\\Lambda$ baryon spectrum from lattice QCD and effective theory","abstract":"The spectrum of the negative-parity spin-1/2 $\\Lambda$ baryons is studied using lattice QCD and hadronic effective theory in a unitarized coupled-channel framework. A direct comparison between the two approaches is possible by considering the hadronic effective theory in a finite volume and with hadron masses and mesonic decay constants that correspond to the situation studied on the lattice. Comparing the energy level spectrum and $SU(3)$ flavor decompositions of the individual states, it is found that the lowest two states extracted from lattice QCD can be identified with one of the two $\\Lambda(1405)$-poles and the $\\Lambda(1670)$ resonance. The quark mass dependences of these two lattice QCD levels are in good agreement with their effective theory counterparts. However, as current lattice QCD studies still rely on three-quark operators to generate the physical states, clear signals corresponding to the meson-baryon scattering states, that appear in the finite volume effective theory calculation, are not yet seen.","primary_cat":"hep-lat","cross_cats":["hep-ph"],"submitted_at":"2020-10-03T03:21:31+00:00","latest_version":2,"source":"arxiv","source_label":"arXiv","source_url":null,"has_pdf":true,"has_source":false,"verdict":null,"confidence":null,"one_line_summary":null,"novelty_score":null,"correctness_risk":null,"formal_verification":null,"upvotes":0,"downvotes":0,"pith_score":0.0,"inbound_count":1,"_links":{"html":"https://pith.science/paper/2010.01270","verdict":"/api/v1/verdicts/2010.01270"}}