Early Decay of Peccei-Quinn Fermion and the IceCube Neutrino Events

TL;DR

This paper proposes a model within the Peccei-Quinn framework where early decay of a long-lived particle explains IceCube's high-energy neutrino observations, aligning particle physics with cosmological history.

Contribution

It constructs a Peccei-Quinn based particle physics model that accounts for IceCube neutrino flux via early decay of a massive long-lived particle, integrating cosmology and neutrino physics.

Findings

The model fits IceCube neutrino data with early decay scenario.

A consistent cosmological history for the long-lived particle is established.

The neutrino flux calculation matches observed IceCube flux.

Abstract

IceCube observed high-energy neutrino flux in the energy region from TeV to PeV. The decay of a massive long-lived particle in the early universe can be the origin of the IceCube neutrino events, which we call an "early decay scenario." In this paper, we construct a particle physics model that contains such a massive long-lived particle based on the Peccei-Quinn model. We calculate the present neutrino flux, taking account of realistic initial energy distributions of particles produced by the decay of the massive long-lived particle. We show that the early decay scenario naturally fits into the Peccei-Quinn model, and that the neutrino flux observed by IceCube can be explained in such a framework. We also see that, based on that model, a consistent cosmological history that explains the abundance of the massive long-lived particle is realized.