Neutrino Emission from Gamma-Ray Burst Fireballs, Revised

TL;DR

This paper revises the neutrino flux predictions from gamma-ray burst fireballs, incorporating detailed energy dependencies and particle physics effects, leading to more accurate estimates that can constrain cosmic ray models with future observations.

Contribution

It provides a comprehensive numerical calculation of neutrino flux from gamma-ray bursts, improving upon analytical models by including full energy dependencies and particle physics effects.

Findings

Neutrino flux normalization reduces by about an order of magnitude.

Spectrum shifts to higher energies with full energy dependence.

Baryonic loading can be constrained with long-term observations.

Abstract

We review the neutrino flux from gamma-ray bursts, which is estimated from gamma-ray observations and used for the interpretation of recent IceCube data, from a particle physics perspective. We numerically calculate the neutrino flux for the same astrophysical assumptions as the analytical fireball neutrino model, including the dominant pion and kaon production modes, flavor mixing, and magnetic field effects on the secondary muons, pions, and kaons. We demonstrate that taking into account the full energy dependencies of all spectra, the normalization of the expected neutrino flux reduces by about one order of magnitude and the spectrum shifts to higher energies, where we can pin down the exact origin of the discrepancies by the re-computation of the analytical models. We also reproduce the IceCube-40 analysis for exactly the same bursts and same assumptions and illustrate the impact of uncertainties. We conclude that the baryonic loading of the fireballs, which is an important control parameter for the emission of cosmic rays, can be constrained significantly with the full-scale experiment after about ten years.