Implications of the Pseudo-Dirac Scenario for Ultra High Energy Neutrinos from GRBs

TL;DR

This paper explores how the pseudo-Dirac neutrino scenario could explain the lower-than-expected neutrino flux from GRBs detected by IceCube, impacting our understanding of UHECR sources and neutrino physics.

Contribution

It investigates the role of active-sterile neutrino oscillations in the pseudo-Dirac scenario to explain the neutrino flux deficit from GRBs.

Findings

Active-sterile neutrino oscillations can reduce detectable neutrino flux.

The scenario has implications for diffuse supernova relic neutrinos.

It challenges the assumption that GRBs are primary UHECR sources.

Abstract

The source of Ultra High Energy Cosmic Rays (UHECR) is still an unresolved mystery. Up until recently, sources of Gamma Ray Bursts (GRBs) had been considered as a suitable source for UHECR. Within the fireball model, the UHECR produced at GRBs should be accompanied with a neutrino flux detectable at the neutrino telescope such as IceCube. Recently, IceCube has set an upper bound on the neutrino flux accompanied by GRBs about 3.7 times below the prediction. We investigate whether this deficit can be explained by the oscillation of the active neutrinos to sterile neutrinos en route from the source to the detectors within the pseudo-Dirac scenario. We then discuss the implication of this scenario for diffuse supernova relic neutrinos.