IceCube Events from Heavy DM decays through the Right-handed Neutrino Portal

TL;DR

This paper proposes a model where heavy dark matter decays via a right-handed neutrino portal, explaining IceCube PeV neutrino events with a specific decay channel and lifetime, and discusses how to produce the correct relic abundance.

Contribution

It introduces a new dark matter decay model involving a $U(1)_X$ gauge symmetry and right-handed neutrinos, fitting IceCube data with a specific decay mode and lifetime.

Findings

Dark matter with ~5 PeV mass can decay into neutrinos consistent with IceCube data.

The neutrino flux from this decay is softer than from other decay channels.

A mechanism for producing the correct dark matter relic abundance is discussed.

Abstract

The recently observed IceCube PeV events could be due to heavy dark matter (DM) decay. In this paper, we propose a simple DM model with extra $U(1)_X$ gauge symmetry and bridge it with standard model particles through heavy right-handed neutrino. The Dirac fermion DM $\chi$ with mass ~5 PeV can dominantly decay into a dark Higgs ($\phi$), the SM Higgs ($h$) and a neutrino ($\nu$). If the lifetime of $\chi$ is ~O($10^{28}$) sec, the resulting neutrino flux can fit data consistently. The neutrino flux from $\chi \rightarrow \phi h \nu$ in our model is softer than the one predicted from $\chi \rightarrow \nu h$, for example. We also discuss a possible mechanism to produce DM with the right relic abundance.