{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"51df2d74889f6da7d6b8dfa20eac566cf61cd3093203171b821f281aca29c07d","created":"2026-10-03T07:18:05Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"9894f730c10c53146753abd54dc18b50afa3c1ecf48b4642eb990b72aff1e72e","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"hep.neutrino-fog.directional-discrimination","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Solar neutrinos push nuclei away from the Sun, while dark matter pushes them along Earth's path through the galaxy. A detector that measures recoil directions could tell them apart, if it can track recoils only a few keV in energy.","posed_since":"","precise":"In the neutrino fog, defined by O'Hare as the region where the discovery-limit index $n = -(d \\ln \\sigma / d \\ln \\mathrm{exposure})^{-1}$ exceeds 2, sensitivity grows slower than $1/\\sqrt{\\mathrm{exposure}}$. The question is the angular resolution, head-tail recognition efficiency and threshold (e.g., in a He:SF6 or CF4 gas time projection chamber) needed to restore n near 1 at WIMP masses 5-10 GeV and cross sections about one order of magnitude below the 8B fog boundary for the chosen target, and the exposure this requires.","problem_ref":null,"references":"","settled_by":"Demonstrated head-tail sensitivity and angular resolution for few-keV nuclear recoils in a prototype, combined with a sensitivity calculation using the measured performance.","status_note":"","title":"Can recoil direction separate dark matter from solar neutrinos?","topic_ref":"8aa34dbf8fe622dfe44455a4a52ccd521c5275a918d302f3967b566a3c2ae8e9"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"237fc79f0868b0378b02cd62d1cb6fb6b46dcfc19d1e449a6666694cc53feb53","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"dff1958c7b4f8fdf44819992e5c4c130a9244de1c6e328c7ceb96e337a8afd63","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"5xt5ONnm3o0jRq1crrlhkDtQu3FTGd-QEM-M7sIk5cNowfCNLWmuvu3GUNvt3c-2OtCskJIc71Ysln1sJ3jzBw"},"schema":"pubphys.envelope/1"},"record_hash":"237fc79f0868b0378b02cd62d1cb6fb6b46dcfc19d1e449a6666694cc53feb53","leaf_index":1568}