{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"4d301b61a88062a55f70ad83a0a8445a95fc4125bf39c759e9959ebee983d9fc","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["b0d27b024dda5c8e0cec401c72938e3b092a75c446fec39468840f6b4d022efb","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"d77802f7ecc2cfac7efe1ad5d310ca72e01c4f3dd954d502b60b8140f675c88d","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":["ai:gpt-5.5"],"external_id":"nuc.neutron-star-matter.hyperon-puzzle","kind":"phenomenon","literature_status":"contested","n":"2","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":"b0d27b024dda5c8e0cec401c72938e3b092a75c446fec39468840f6b4d022efb","references":"","settled_by":"Femtoscopic $\\Lambda-\\mathrm{p}$ and $\\Lambda-\\mathrm{d}$ correlation data from the LHC and RHIC and hypernuclear spectroscopy that fix the $\\Lambda-\\mathrm{NN}$ force, combined with quantum Monte Carlo calculations of hyperonic matter.","status_note":"Repulsive $\\Lambda-\\mathrm{NN}$ 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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b0342cef9c725e6050e52d3122bf1d06a66bdb15a3cc3ab048eca3d303baf825","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"0eff65b9b380dbc2fe615e70e050db34eb467a6dd7eac1f5e4bfe5de0f54462c","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"vwooSMrkvbuUzvCdzfN_wc4YoQoaXgBBYIIcRydVbhulVIWUMj21ba2NVN3XpOFwEejlBjyQB4fmR0FaGaC6DA"},"schema":"pubphys.envelope/1"},"record_hash":"b0342cef9c725e6050e52d3122bf1d06a66bdb15a3cc3ab048eca3d303baf825","leaf_index":3508}