{"paper":{"title":"Optimal Calibration-Free Observable for the Nucleon-Coupling Ratio in a Dual-Alkali Comagnetometer for Dark Matter Searches","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["physics.atom-ph"],"primary_cat":"hep-ph","authors_text":"Eli Sarid, Menachem Givon, Ron Folman, Yevgeny Kats, Yonathan Japha, Yossi Rosenzweig","submitted_at":"2026-08-07T17:49:45Z","abstract_excerpt":"A dual-alkali single-cell $^{87}$Rb-$^{39}$K-$^{3}$He comagnetometer can read an axionlike dark matter signal through two optical-rotation channels, encoding the ratio $\\mathcal{R}=\\xi_n/\\xi_p$ of the field's neutron and proton spin couplings in their relative response. The inter-species phase difference $\\Delta\\varphi$ has been proposed as a calibration-free readout that is sensitive to $\\mathcal{R}$. Treating the extraction of $\\mathcal{R}$ as a statistical estimation problem, we show that the optimal observable is the complex inter-channel ratio, which splits into $\\Delta\\varphi$ and an amp"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2608.07456","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2608.07456/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}