Effects of conversions for high energy neutrinos originating from cosmological gamma-ray burst fireballs

TL;DR

This paper investigates how neutrino conversions near gamma-ray burst fireballs, influenced by magnetic moments and equivalence principle violations, can enhance high-energy tau neutrino fluxes from cosmological sources.

Contribution

It introduces a model combining neutrino magnetic moments and VEP effects to explain potential resonant neutrino conversions near GRBs, predicting increased tau neutrino fluxes.

Findings

Resonant spin-flavour precession can occur for specific parameters.

Enhanced tau neutrino fluxes are possible near GRBs.

VEP and magnetic moments significantly influence neutrino oscillations.

Abstract

We study neutrino conversions in the recently envisaged source of high energy ($E \geq 10^{6}$ GeV) neutrinos, that is, in the vicinity of cosmological gamma-ray burst fireballs (GRB). We consider mainly the possibility of neutrino conversions due to an interplay of neutrino transition magnetic moment, $\mu$, and the violation of equivalence principle (VEP), parameterized by $\Delta f$, in a reasonable strength of magnetic field in the vicinity of the GRB. We point out that for $\Delta f \sim 10^{-25}(\delta m^2/1 {eV}^2)$, a resonant spin-flavour precession between $\bar{\nu}_{\mu}$ and $\nu_{\tau}$ may occur in the vicinity of GRB for $\mu \sim 10^{-12} \mu_{B}$ ($\mu_{B}$ is Bohr magneton), thus enhancing the expected high energy $\nu_{\tau}$ flux from GRBs.