{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"981bf2d74f59ec2de66650a8eadee2171ee1d731d663468c2343a9d516aadebe","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["237fc79f0868b0378b02cd62d1cb6fb6b46dcfc19d1e449a6666694cc53feb53","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"e9d3fd60b2fcfb77c55f7c08848ef06ca7a0d7781747f921357ebe218893df72","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":"2","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:$\\mathrm{SF_6}$ or $\\mathrm{CF_4}$ 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":"237fc79f0868b0378b02cd62d1cb6fb6b46dcfc19d1e449a6666694cc53feb53","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":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c73e2edc43ab37935219deb70df5c9e45d70ec845c4b134afa9ed481a9072ec0","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"06fdf59ecc10edbea3e304a3369d5e243a9afe27eab28e82207edf9d7acacf39","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Z2L0fRC61xXOhzzHr-pdtpCRwxCtVPLuXfQNf2vt6aHEoQp4tWLXxVe0ZEwFwxS9XI5ICXuf5JYCdD-lu8yRCQ"},"schema":"pubphys.envelope/1"},"record_hash":"c73e2edc43ab37935219deb70df5c9e45d70ec845c4b134afa9ed481a9072ec0","leaf_index":3370}