arXiv · 2611.06284
A search for sterile neutrinos at ultrahigh energies at the Pierre Auger Observatory
Abstract
We investigate the sensitivity of the Pierre Auger Observatory to sterile neutrinos with masses in the MeV-to-100 MeV range. To this end, we consider a minimal $3+1$ framework in which a single sterile state mixes mainly with the $ν_τ$ flavor through an active--sterile mixing angle $θ_N$ to produce a mass eigenstate $N_1$. At ultrahigh energies, $N_1$ neutrinos can traverse substantial chord lengths through the Earth and interact through their active component, producing $τ$ leptons that may emerge near the surface and decay in the atmosphere, thereby generating detectable air showers. We compute the corresponding exposures with a detailed Monte Carlo simulation of neutrino propagation, interactions, $τ$ energy losses and decay, and derive upper limits at $90\%$ confidence level on an isotropic diffuse flux of $N_1$ neutrinos. For an $E^{-2}$ spectrum, we obtain $E^2Φ_N\leq 2\times10^{-9}\sin^{-2}θ_N\,\mathrm{GeV\,cm^{-2}\,sr^{-1}\,s^{-1}}$ over $0.3$--$200$ EeV for $\sin^2θ_N\lesssim10^{-1}$. We further consider $N_1$ neutrinos arising from the decay of a superheavy dark-matter particle. For a benchmark dark-matter mass of $10^{13}$ GeV, we derive constraints on the active--sterile mixing angle and dark-matter lifetime for sterile-neutrino masses of $10$ and $100$ MeV. These results illustrate the potential of the Observatory to probe long-lived weakly interacting particles.
Explore related subjects
Keep this discovery
Explore connections, maps & timelines
The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu, M. Aglietta, M. Ahmed, I. Allekotte, K. Almeida Cheminant, R. Aloisio, J. Alvarez-Muñiz, A. Ambrosone, J. Ammerman Yebra, L. Anchordoqui, B. Andrada, L. Andrade Dourado, L. Apollonio, C. Aramo, J. C. Arteaga Velázquez, P. Assis, G. Avila, E. Avocone, A. Bakalova, Y. Balibrea, A. Baluta, F. Barbato, A. Bartz Mocellin, O. Batalla Cruz, J. P. Behler, C. Berat, M. E. Bertaina, M. Bianciotto, P. L. Biermann, V. Binet, K. Bismark, T. Bister, J. Biteau, J. Blazek, J. Blümer, M. Boháčová, D. Boncioli, C. Bonifazi, P. Boril, N. Borodai, J. Brack, P. G. Brichetto Orquera, S. Buitink, A. Bwembya, T. R. Caba Pineda, K. S. Caballero-Mora, S. Cabana-Freire, L. Caccianiga, J. Caraça-Valente, R. Caruso, A. Castellina, F. Catalani, G. Cataldi, L. Cazon, M. Cerda, B. Čermáková, A. Cermenati, K. Cerny, J. A. Chinellato, J. Chudoba, L. Chytka, R. W. Clay, A. C. Cobos Cerutti, R. Colalillo, R. Conceição, G. Consolati, M. Conte, F. Convenga, D. Correia dos Santos, P. J. Costa, C. E. Covault, M. Cristinziani, C. S. Cruz Sanchez, S. Dasso, K. Daumiller, B. R. Dawson, R. M. de Almeida, E. -T. de Boone, B. de Errico, J. de Jesús, S. J. de Jong, J. R. T. de Mello Neto, I. De Mitri, D. de Oliveira Franco, F. de Palma, V. de Souza, E. De Vito, A. Del Popolo, O. Deligny, N. Denner, K. Denner Syrokvas, L. Deval, A. di Matteo, C. Dobrigkeit, J. C. D'Olivo, L. M. Domingues Mendes, T. Dominguez, Y. Dominguez Ballesteros. 2026-11-04. A search for sterile neutrinos at ultrahigh energies at the Pierre Auger Observatory. https://arxiv.org/abs/2611.06284
Cite the original work for its findings. Save a collection to share your selection of sources.