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arXiv · 2402.00985

Upper Limits on the Cosmic Neutrino Background from Cosmic Rays

Mar Císcar-Monsalvatje·Gonzalo Herrera·Ian M. Shoemaker
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Abstract

Extragalactic and galactic cosmic rays scatter with the cosmic neutrino background during propagation to Earth, yielding a flux of relic neutrinos boosted to larger energies. If an overdensity of relic neutrinos is present in galaxies, and neutrinos are massive enough, this flux might be detectable by high-energy neutrino experiments. For a lightest neutrino of mass $m_{\nu} \sim 0.1$ eV, we find an upper limit on the local relic neutrino overdensity of $\sim 10^{13}$ and an upper limit on the relic neutrino overdensity at TXS 0506+056 of $\sim 10^{10}$. Future experiments like GRAND or IceCube-Gen2 could improve these bounds by orders of magnitude.

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Mar Císcar-Monsalvatje, Gonzalo Herrera, Ian M. Shoemaker. 2024-02-01. Upper Limits on the Cosmic Neutrino Background from Cosmic Rays. https://doi.org/10.1103/physrevd.110.063036

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