{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f224f0ccac36851181b7cba91f4139e627435c05491410c3d057c2e502e155a3","created":"2026-10-03T07:18:08Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"cbd3b8c7cea6b5677a49f388b8bd2135c065412579a138d89e43e8ddd4e5621b","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"nuc.stellar-reaction-rates.c12c12-resonances","kind":"well-posed","literature_status":"contested","n":"1","parents":[],"plain":"Carbon burning in massive stars and in exploding white dwarfs starts when two carbon-12 nuclei fuse, and the fusion probability may be boosted by narrow resonances (energies where the two nuclei briefly form a long-lived state). Direct and indirect experiments disagree on whether such resonances exist at the stellar energies.","posed_since":"","precise":"Determine the total $\\mathrm{12C}+\\mathrm{12C}$ fusion S*-factor (alpha plus proton channels) for $E_{\\mathrm{cm}}=1.5\\ \\text{to}\\ 2.5\\,\\mathrm{MeV}$, the Gamow window for $T=5e8\\ \\text{to}\\ 1e9\\,\\mathrm{K}$, including the presence, energies and strengths of any resonances, and hence the reaction rate at $T=5e8\\ \\text{to}\\ 1e9\\,\\mathrm{K}$ to 20 percent. The answer must reconcile direct particle-gamma coincidence data, which extend down to about $E_{\\mathrm{cm}} \\sim 2.2\\,\\mathrm{MeV}$, with indirect Trojan-horse extractions that claim strong resonant enhancement below 2 MeV.","problem_ref":null,"references":"","settled_by":"A direct measurement of the $\\alpha$ and proton channels down to $E_{\\mathrm{cm}} \\sim 1.5\\ \\mathrm{MeV}$ with background low enough to resolve or exclude resonances, cross-checked against the Trojan-horse normalization.","status_note":"Direct STELLA data were refined in 2025 and new Trojan-horse data appeared in 2026; direct and indirect rates remain in tension below $E_{\\mathrm{cm}} \\sim 2.5\\,\\mathrm{MeV}$.","title":"Resonances in 12C+12C fusion inside the carbon-burning Gamow window","topic_ref":"a34c6b5ed7af37b4290d97a2613b13b71248636c2138e338345ab4d03e765618"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2bbb85e052d4d8bb516219c1b58777d3962973bd28eedd1576c47c1ca7cfec03","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"1024d1e834f2f9dfcd436bde8e5febcdd06fb5e1ad906c3d7fc41dbc8a973c45","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"IE5TLAvWtlAWso4WzMzVzdy3p8CRnfisnANMQKXjCDygfKVuZSASlatYk9bHhAZxdBs5N5qXwInRQ8Qyv9JGAQ"},"schema":"pubphys.envelope/1"},"record_hash":"2bbb85e052d4d8bb516219c1b58777d3962973bd28eedd1576c47c1ca7cfec03","leaf_index":1813}