Early decay of Peccei–Quinn fermion and the IceCube neutrino events

• Main Authors: Yohei Ema, Takeo Moroi
• Format: Article
• Language: English
• Published: Elsevier 2016-11-01
• Series: Physics Letters B
• Online Access: http://www.sciencedirect.com/science/article/pii/S0370269316305524

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.