{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"c8c40a8545498cdfa9347f1d80f0db51ec267cf78cd973f5182157987f31c983","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["59c70c58ebc1de8bff7fc3398a95a4795b7d421f35be6bf7283b56f00e4e3db6","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"e47626a85123a0379520ec114a9ba23460cac7712246f90fca008d1fbd9bd751","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":["ai:gpt-5.5"],"external_id":"nuc.qcd-phase-diagram.critical-point","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"At zero net baryon density, ordinary matter turns into quark-gluon plasma smoothly as it heats. At higher density the change may become abrupt, and the critical point is where smooth turns abrupt, if it exists.","posed_since":"1989","precise":"Determine whether the chiral crossover line $T_{\\mathrm{pc}}(\\mu_B)$ ($T_{\\mathrm{pc}}(0)$ about $156\\,\\mathrm{MeV}$, $\\mu_B$ the baryon chemical potential) ends at a critical point $(T_c, \\mu_B,c)$ beyond which the transition is first order, and locate it. Lattice QCD disfavors a critical point at $\\mu_B/T$ below about 3. Answer: yes or no, and $(T_c, \\mu_B,c)$ with uncertainty.","problem_ref":"59c70c58ebc1de8bff7fc3398a95a4795b7d421f35be6bf7283b56f00e4e3db6","references":"","settled_by":"A first-principles calculation reaching $\\mu_B/T > 3$, or an experimentally established nonmonotonic fluctuation signal reproduced by dynamical critical-point modeling.","status_note":"Functional-method and lattice-based extrapolations from 2021 to 2025 placed a possible critical point near $\\mu_B$ of roughly 400 to 650 MeV, beyond direct lattice reach as of 2026.","title":"Existence and location of the QCD critical point","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"fe746579b3df23655b09c45ab739b7856310389350a2dc5906548304e70eb8a7","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"2f05615a59bd733c4e1dcc7704675e5414255d331c3a1e9b34b2b72cc9b831e5","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"2tlCDSUaSQgAar4uEo7b2hC7LSrTeLtNZDVQqKsL9fbfZD9XUd5EbXMwE7VuOiU3tTimGGJ_ORu7LXE65uxTCA"},"schema":"pubphys.envelope/1"},"record_hash":"fe746579b3df23655b09c45ab739b7856310389350a2dc5906548304e70eb8a7","leaf_index":3528}