Probing long-lived particle production in muon decays at the SNS with a highly capable hydrocarbon detector
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) is a prolific muon producer, making it an ideal location for studying dark sector particles produced in muon decays at rest. In this paper, we explore sub-GeV dark particle detection possibilities in a tons-scale, highly capable hydrocarbon scintillator ($HC^2$) detector at the SNS. We consider a search for $e^+e^-$ final states produced by decays of long-lived, $O(10-100)$ MeV axion-like particles and heavy neutral leptons. The $HC^2$ technology space, exemplified by the PROSPECT and Mobile Antineutrino Demonstrator detectors, offers strong rejection capabilities for the cosmic ray backgrounds that would normally dominate this search. By benchmarking on-surface cosmic ray signatures with data from PROSPECT at ORNL, we generate robust predictions for a multi-year SNS deployment of a range of $HC^2$ detector implementations. Results indicate the potential for order-of-magnitude improvements in sensitivity to axion-like particles and heavy neutral leptons in the 10-100 MeV mass regime compared to current global limits. We also comment on the neutrino detection possibilities of a $HC^2$ deployment at the SNS.
Authors
- A. B. Hansell (ORCID: https://orcid.org/0000-0003-2586-4019)
- H. Pieter Mumm (ORCID: https://orcid.org/0000-0003-4204-9817)
- T. Classen
- D. Venegas-Vargas
- E.P Bernard (ORCID: https://orcid.org/0000-0002-2944-5359)
- A. Galindo-Uribarri
- N.S. Bowden
- J. Wilhelmi (ORCID: https://orcid.org/0000-0002-5530-5130)
- K.M. Heeger
- A. Erickson
- A. J. Conant
- C. D. Bass
- J. Maricic
- S. Gokhale
- R. Rosero
- S. Hans
- C.D. Bryan
- R. Carr
- N. Patel (ORCID: https://orcid.org/0000-0001-8744-4461)
- M. Andriamirado
- G. Deichert
- J.R. Newby
- A. B. Balantekin (ORCID: https://orcid.org/0000-0002-2999-0111)
- C. Roca
- J. Koblanski (ORCID: https://orcid.org/0009-0008-3833-6921)
- S. K. Ghosh (ORCID: https://orcid.org/0000-0002-4711-9733)
- C. E. Lane
- Russell G. Neilson (ORCID: https://orcid.org/0000-0002-2729-5131)
- D. Norcini
- R. Milincic
- A. Lozano Sanchez
- A. Irani
- F. Machado
- T. E. Haugen (ORCID: https://orcid.org/0000-0002-8222-116X)
- M. Fuller
- N. Craft
- M. P. Mendenhall
- M. Hostert
- O.Benevides Rodrigues
- X. Zhang
- P. E. Mueller
- C. Grant
- S. Urrea
- B. R. Littlejohn
- M. Yeh
- A. M. Meyer
Publication Details
- Journal
- Physical review. D/Physical review. D.
- Published
- 2026-11-06
- DOI
- https://doi.org/10.1103/xtl2-wj6n
- Citations
- 1
- Primary Topic
- Particle Detector Development and Performance
- Type
- article
- Field-Weighted Citation Impact
- 0.85
Funders
- U.S. Department of Defense
- U.S. Department of Energy
- Battelle
- Yale University
- Drexel University
- Temple University
- National Institute of Standards and Technology
- Office of Science
- U.S. Navy
- High Energy Physics
- Laboratory Directed Research and Development
- U.S. Naval Academy
- Lawrence Livermore National Laboratory
- Oak Ridge National Laboratory
- Brookhaven National Laboratory