Super Heavy Dark Matter and UHECR Anisotropy at Low Energy

TL;DR

This paper explores Super Heavy Dark Matter as a potential, albeit subdominant, source of Ultra High Energy Cosmic Rays, analyzing its signatures in composition and anisotropy at the Auger observatory.

Contribution

It investigates the role of Super Heavy Dark Matter in producing UHECRs and discusses observable signatures at the Auger observatory, especially in cases without the AGASA excess.

Findings

SHDM can produce a subdominant UHECR flux consistent with observations.

Expected chemical composition and anisotropy signatures are discussed for Auger.

SHDM decay spectrum follows approximately E^{-1.9}.

Abstract

Super Heavy quasi-stable particles are naturally produced in the early universe and could represent a substantial fraction of the Dark Matter: the so-called Super Heavy Dark Matter (SHDM). The decay of SHDM represents also a possible source of Ultra High Energy Cosmic Rays (UHECR), with a reliably calculated spectrum of the particles produced in the decay $(\propto E^{-1.9})$. The SHDM model for the production of UHECR can explain quantitatively only the excess of UHE events observed by AGASA. In the case of an observed spectrum not showing the AGASA excess the SHDM model can provide only a {\it subdominant} contribution to the UHECR flux. We discuss here the basic features of SHDM for the production of a {\it subdominant} UHECR flux, we refer our study to the possible signatures of the model at the Auger observatory discussing in particular the expected chemical composition and anisotropy.