Lunar neutrinos

TL;DR

This paper models lunar neutrino emissions resulting from cosmic ray interactions, highlighting their potential as a unique astrophysical source and their sensitivity to lunar surface properties, despite observational challenges.

Contribution

It provides the first detailed calculation of low-energy lunar neutrino spectra and discusses their potential for multimessenger astronomy and lunar surface analysis.

Findings

Lunar neutrinos have distinctive spectral features.

Neutrino flux is sensitive to lunar surface density.

Detection is challenging but feasible with future experiments.

Abstract

Cosmic rays bombard the lunar surface producing mesons, which attenuate inside the regolith. They get slower and decay weakly into mostly sub-GeV neutrinos leaving the surface. Thus the Moon shines in neutrinos. Here we calculate spectra of low energy neutrinos, which exhibit bright features potentially recognisable above isotropic neutrino background in the direction towards the Moon. Their observation, though a very challenging task for future neutrino large volume experiments, would make the Moon the nearest astrophysical source for which the concept of multimessenger astronomy works truly. Remarkably, some features of the lunar neutrino flux are sensitive to the surface mass density of the Moon.