{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"2d5a25f980f4429ae7f5983715259bfcc8279c27eb4b20932b1eec5e510128b2","created":"2026-10-03T07:17:56Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"c330673b81793a004909ee2e45eac6661a8f640a3f2749e0a260d1c994577c84","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":"1","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 $70\\,\\mathrm{percent}$ polarization up to $275\\,\\mathrm{GeV}$ in an electron-ion collider hadron ring.","problem_ref":null,"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":"9b02c27128b03f7c327a7c52a19b27e591b0902b0604205d7218c8dbadece62a"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"188a406905536ae5a28db1bacc15b2c6c0ba14b055b5ebdcebc4d3d731198400","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"774993c233e60117509c6fe520190ccc27b49d3ed17a09738a5dfcd38275d5d9","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Oe0fyXYjK13sKxahIwVTqet0u1gZVwX85Tmx_0X9wrh02QwxMFads-f3RnV8c5iUtcRmEYgR8ZNfIuDAs9AWDg"},"schema":"pubphys.envelope/1"},"record_hash":"188a406905536ae5a28db1bacc15b2c6c0ba14b055b5ebdcebc4d3d731198400","leaf_index":688}