{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"7403948c849f0341920068ac293ff4af7fbba6cb5f7f70f2abea65173ba29033","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"3850ae6d1069a3a9b889d1483ba1de6fe4938c3bf0552554161c39f7f7839623","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"nuc.neutron-star-matter.hyperon-puzzle","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"At high density it becomes energetically favorable to turn some neutrons into hyperons (baryons containing a strange quark), which softens the matter so much that most models cannot then support stars of two solar masses. Yet such stars are observed.","posed_since":"","precise":"With hyperon-nucleon (YN) and hyperon-nucleon-nucleon (YNN) forces constrained by hypernuclear binding energies, femtoscopic correlations and lattice QCD, determine the density at which $\\Lambda$ and $\\Sigma-$ hyperons appear and whether $M_{\\mathrm{TOV}} \\ge 2\\ \\text{solar masses}$ survives. Answer: the mechanism (repulsive YNN forces, early quark deconfinement, or absence of hyperons) and the interaction parameters that produce it.","problem_ref":null,"references":"","settled_by":"Femtoscopic Lambda-p and Lambda-d correlation data from the LHC and RHIC and hypernuclear spectroscopy that fix the Lambda-NN force, combined with quantum Monte Carlo calculations of hyperonic matter.","status_note":"Repulsive Lambda-NN forces fitted to hypernuclei can suppress hyperons (Lonardoni et al., 2015), but the three-body force remained poorly constrained as of 2026.","title":"How do hyperons fit inside two-solar-mass neutron stars?","topic_ref":"dc9703fcc2930752e3222472fa4f0774fcc6cb72d19c4033b77e3e2b58d0fcb3"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b0d27b024dda5c8e0cec401c72938e3b092a75c446fec39468840f6b4d022efb","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"4d19f24936694e4dd679c98fb37563114ef478c8895da59c03a862fd4a95855a","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"ozUOVKzITd0msWYUQ65ovFzXSCcn9VbuLkmIjp3ettm0scv_KkNxyynNjbZGaCaRoDno4p-UMg_QAX_AsGEPDg"},"schema":"pubphys.envelope/1"},"record_hash":"b0d27b024dda5c8e0cec401c72938e3b092a75c446fec39468840f6b4d022efb","leaf_index":1777}