2025/06/27 by Haichuan Cao, Cao, Haichuan, D. Koltick +1
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Neutrino Physics Research
paper · pdf · doi:10.48550/arxiv.2506.22659
openalex publication_date 2025/06/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
An independent indirect detection search for Dark Matter-Matter (DM-M) interactions is undertaken to set cross section limits based on neutron production data collected by the NMDS-II detector for 1440 hours at 1166 m.w.e. and 6504 hours at 583 m.w.e.. The detector system consists of a 30 cm cube Pb-target instrumented with 60 3He neutron counters. The neutron detector system calibrated with a 252Cf source yields a single particle detection efficiency of 23.2%±1.2%. During data collection, the highest neutron multiplicity event observed 54 neutrons. The neutron multiplicity, n, distribution, fits well to a power law k × n-p, for both the data and cosmic ray muon induced neutron production in Geant4 simulations. Two DM-M interaction models were used to set limits. The first, a spallation model, assumes a single proton with kinetic energy equal to the DM-M interaction energy. The other, a fire-ball model assumes an annihilation between DM-M producing pions with a limiting Hagedorn temperature. The two extreme models produce similar upper DM-M cross section limits over the DM mass range between 300 MeV to 100 GeV. Limits assume all the DM energy is deposited in the Pb-target. Spin independent limits, proportional to A-2, are at the level ~10-45~ cm2. Spin dependent limits, proportional to A-1, are at the level, 2× 10-42~cm2.