Neutrino yield from Galactic cosmic rays

TL;DR

This paper calculates the neutrino flux produced by cosmic ray interactions in the Galaxy, analyzing how different cosmic ray compositions influence the expected neutrino signals, and discusses implications for IceCube observations.

Contribution

It provides the first detailed calculation of Galactic neutrino yields using QGSJET-II and explores the impact of different cosmic ray flux models on neutrino flux predictions.

Findings

Neutrino flux shape depends on cosmic ray composition.

Galactic neutrino flux likely not responsible for IceCube excess.

Proton component dominates the neutrino flux above 10^14 eV.

Abstract

We calculate the neutrino yield from collisions of cosmic ray (CR) nuclei on gas using the event generator QGSJET-II. We present first the general characteristics and numerical results for the neutrino yield assuming power-law fluxes for the primary CR nuclei. Then we use three parameterisations for the Galactic CR flux to derive the neutrino yield for energies around and above the knee. The shape and the normalization of the resulting neutrino flux above $\sim 10^{14}$ eV depends on the composition of the Galactic CR flux employed, but is generally dominated by its proton component. The spectral shape and magnitude of the neutrino flux suggest that the IceCube excess is not connected to interactions of Galactic sea CRs. If a fraction of these events has a Galactic origin, then they may be caused by CR overdensities around recent close-by Galactic sources.