{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"2120f73f52b277f8cc649e539f4e825293203520e539af12c3ac488849fdaf76","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["188a406905536ae5a28db1bacc15b2c6c0ba14b055b5ebdcebc4d3d731198400","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"69d1e58cd7fba250198e07d56c0d2847558d048e3f5feb896d5e1ef2bfd625d5","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"beams.polarized-beams.snake-polarization-loss","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Even with special magnets that flip the spin each turn, protons accelerated to hundreds of GeV lose part of their polarization, for reasons not fully modeled.","posed_since":"","precise":"RHIC accelerates polarized protons to $255\\,\\mathrm{GeV}$ with two full Siberian snakes, losing part of the injected polarization during acceleration through intrinsic and imperfection spin resonances. Determine the mechanism of the residual loss (higher-order snake resonances, overlap of intrinsic and imperfection resonances, spin-tune spread) and predict whether $N_s$ snakes preserve more than $70\\%$ polarization up to $275\\,\\mathrm{GeV}$ in an electron-ion collider hadron ring.","problem_ref":"188a406905536ae5a28db1bacc15b2c6c0ba14b055b5ebdcebc4d3d731198400","references":"","settled_by":"Spin tracking that reproduces measured RHIC polarization versus energy and is then applied to the target lattice.","status_note":"","title":"Residual polarization loss of protons accelerated with Siberian snakes","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"f73d1b83bc02cbbd6a117f161532092f20d37f4922ea58142a507fd118044b86","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"4d19323f2872ce6aa95022402ad7bdc8a0d8e41401f4d0aac5764dbf8691c993","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"tQJHwf0q5VZV0ZQuAj-U_Og6BHI5WaSOAq5Mf_w9iE61m1UCEfS0ZJ-44P4s5nFPetzA1xctHrGSR1UGB6PMDA"},"schema":"pubphys.envelope/1"},"record_hash":"f73d1b83bc02cbbd6a117f161532092f20d37f4922ea58142a507fd118044b86","leaf_index":2512}