{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/long-exposure-nustar-constraints-on-decaying","title":"Long-Exposure NuSTAR Constraints on Decaying Dark Matter in the Galactic Halo","arxiv_id":"2207.04572","date":"2022-07-11","proceeding":null,"authors":["Brandon M. Roach","Steven Rossland","Kenny C. Y. Ng","Kerstin Perez","John F. Beacom","Brian W. Grefenstette","Shunsaku Horiuchi","Roman Krivonos","Daniel R. Wik"],"abstract":"We present two complementary NuSTAR x-ray searches for keV-scale dark matter decaying to mono-energetic photons in the Milky Way halo. In the first, we utilize the known intensity pattern of unfocused stray light across the detector planes -- the dominant source of photons from diffuse sources -- to separate astrophysical emission from internal instrument backgrounds using ${\\sim}$7-Ms/detector deep blank-sky exposures. In the second, we present an updated parametric model of the full NuSTAR instrument background, allowing us to leverage the statistical power of an independent ${\\sim}$20-Ms/detector stacked exposures spread across the sky. Finding no evidence of anomalous x-ray lines using either method, we set limits on the active-sterile mixing angle $\\sin^2(2\\theta)$ for sterile-neutrino masses 6--40 keV. The first key result is that we strongly disfavor a ${\\sim}$7-keV sterile neutrino decaying into a 3.5-keV photon. The second is that we derive leading limits on sterile neutrinos with masses ${\\sim}$15--18 keV and ${\\sim}$25--40 keV, reaching or extending below the Big Bang Nucleosynthesis limit. In combination with previous results, the parameter space for the Neutrino Minimal Standard Model ($\\nu$MSM) is now nearly closed.","url_abs":"https://arxiv.org/abs/2207.04572v4","url_pdf":"https://arxiv.org/pdf/2207.04572v4.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"long-exposure-nustar-constraints-on-decaying","repo_url":"https://github.com/roachb/nustar-blanksky","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}