More Like this

1. Probing self-interacting sterile neutrino dark matter with the diffuse supernova neutrino background

   https://doi.org/10.1103/PhysRevD.108.123011  

   Balantekin, A. Baha ; Fuller, George M. ; Ray, Anupam ; Suliga, Anna M. ( December 2023 , Physical Review D)

   The neutrinos in the diffuse supernova neutrino background (DSNB) travel over cosmological distances and this provides them with an excellent opportunity to interact with dark relics. We show that a cosmologically significant relic population of keV-mass sterile neutrinos with strong self-interactions could imprint their presence in the DSNB. The signatures of the self-interactions would be “dips” in the otherwise smooth DSNB spectrum. Upcoming large-scale neutrino detectors, for example Hyper-Kamiokande, have a good chance of detecting the DSNB and these dips. If no dips are detected, this method serves as an independent constraint on the sterile neutrino self-interaction strength and mixing with active neutrinos. We show that relic sterile neutrino parameters that evade x-ray and structure bounds may nevertheless be testable by future detectors like TRISTAN, but may also produce dips in the DSNB which could be detectable. Such a detection would suggest the existence of a cosmologically significant, strongly self-interacting sterile neutrino background, likely embedded in a richer dark sector. 

   more » « less
2. Can Neutrino Self-interactions Save Sterile Neutrino Dark Matter?

   https://doi.org/10.3847/2041-8213/acf049  

   An, Rui ; Gluscevic, Vera ; Nadler, Ethan O. ; Zhang, Yue ( August 2023 , The Astrophysical Journal Letters)

   Sterile neutrinos only interact with the standard model through the neutrino sector, and thus represent a simple dark matter (DM) candidate with many potential astrophysical and cosmological signatures. Recently, sterile neutrinos produced through self-interactions of active neutrinos have received attention as a particle candidate that can yield the entire observed DM relic abundance without violating the most stringent constraints from X-ray observations. We examine consistency of this production mechanism with the abundance of small-scale structure in the universe, as captured by the population of ultrafaint dwarf galaxies orbiting the Milky Way, and derive a lower bound on the sterile-neutrino particle mass of 37 keV. Combining these results with previous collider and X-ray limits excludes 100% sterile-neutrino DM produced by strong neutrino self-coupling, mediated by a heavy (≳1 GeV) scalar; however, data permits sterile-neutrino DM production via a light mediator.

    

   more » « less
3. Limits on Astrophysical Antineutrinos with the KamLAND Experiment

   https://doi.org/10.3847/1538-4357/ac32c1  

   Abe, S. ; Asami, S. ; Gando, A. ; Gando, Y. ; Gima, T. ; Goto, A. ; Hachiya, T. ; Hata, K. ; Hayashida, S. ; Hosokawa, K. ; et al ( January 2022 , The Astrophysical Journal)

   We report on a search for electron antineutrinos (${\overline{\nu }}_e$) from astrophysical sources in the neutrino energy range 8.3–30.8 MeV with the KamLAND detector. In an exposure of 6.72 kton-year of the liquid scintillator, we observe 18 candidate events via the inverse beta decay reaction. Although there is a large background uncertainty from neutral current atmospheric neutrino interactions, we find no significant excess over background model predictions. Assuming several supernova relic neutrino spectra, we give upper flux limits of 60–110 cm⁻²s⁻¹(90% confidence level, CL) in the analysis range and present a model-independent flux. We also set limits on the annihilation rates for light dark matter pairs to neutrino pairs. These data improve on the upper probability limit of⁸B solar neutrinos converting into${\overline{\nu }}_e$,$P_{{\nu }_e\to {\overline{\nu }}_e}<3.5\times {10}^{-5}$(90% CL) assuming an undistorted${\overline{\nu }}_e$shape. This corresponds to a solar${\overline{\nu }}_e$flux of 60 cm⁻²s⁻¹(90% CL) in the analysis energy range.

    

   more » « less
4. Review of uncertainties in the cosmic supernova relic neutrino background

   https://doi.org/10.1142/S0217732320300116  

   Mathews, G. J. ; Boccioli, L. ; Hidaka, J. ; Kajino, T. ( August 2020 , Modern Physics Letters A)

   We review the computation of and associated uncertainties in the current understanding of the relic neutrino background due to core-collapse supernovae, black hole formation and neutron star merger events. We consider the current status of uncertainties due to the nuclear equation of state (EoS), the progenitor masses, the source supernova neutrino spectrum, the cosmological star formation rate, the stellar initial mass function, neutrino oscillations, and neutrino self-interactions. We summarize the current viability of future neutrino detectors to distinguish the nuclear EoS and the temperature of supernova neutrinos via the detected relic supernova neutrino spectrum. 

   more » « less
5. Time-delayed neutrino emission from supernovae as a probe of dark matter-neutrino interactions

   https://doi.org/10.1088/1475-7516/2023/04/019  

   Carpio, Jose Alonso ; Kheirandish, Ali ; Murase, Kohta ( April 2023 , Journal of Cosmology and Astroparticle Physics)

   Abstract Thermal MeV neutrino emission from core-collapse supernovae offers a unique opportunity to probe physics beyond the Standard Model in the neutrino sector. The next generation of neutrino experiments, such as DUNE and Hyper-Kamiokande, can detect 𝒪(10 3 ) and 𝒪(10 4 ) neutrinos in the event of a Galactic supernova, respectively. As supernova neutrinos propagate to Earth, they may interact with the local dark matter via hidden mediators and may be delayed with respect to the initial neutrino signal. We show that for sub-MeV dark matter, the presence of dark matter-neutrino interactions may lead to neutrino echoes with significant time delays. The absence or presence of this feature in the light curve of MeV neutrinos from a supernova allows us to probe parameter space that has not been explored by dark matter direct detection experiments. 

   more » « less