Diffuse flux of galactic neutrinos and gamma rays

TL;DR

This paper models the galactic neutrino and gamma-ray fluxes resulting from cosmic ray interactions, highlighting their energy dependence and comparison with atmospheric backgrounds, using multiple simulation tools.

Contribution

It provides detailed flux calculations across a wide energy range using various hadronic interaction models and correlates cosmic-ray density with galactic magnetic fields.

Findings

Galactic neutrino flux exceeds atmospheric flux above 1 PeV.

At IceCube energies, galactic flux is four times smaller than atmospheric from forward-charm decays.

Fluxes depend strongly on cosmic-ray composition at high energies.

Abstract

We calculate the fluxes of neutrinos and gamma rays from interactions of cosmic rays with interstellar matter in our galaxy. We use EPOS-LHC, SIBYLL and GHEISHA to obtain the yield of these particles in proton, helium and iron collisions at kinetic energies between 1 and 10^8 GeV, and we correlate the cosmic ray density with the mean magnetic field strength in the disk and the halo of our galaxy. We find that at E>1 PeV the fluxes depend very strongly on the cosmic-ray composition, whereas at 1-5 GeV the main source of uncertainty is the cosmic-ray spectrum out of the heliosphere. We show that the diffuse flux of galactic neutrinos becomes larger than the conventional atmospheric one at E>1 PeV, but that at all IceCube energies it is 4 times smaller than the atmospheric flux from forward-charm decays.