# Hunting for super-heavy dark matter with the highest-energy cosmic rays

## TL;DR

This paper uses null results from the Pierre Auger Observatory to set new limits on super-heavy dark matter particle decay and discusses future detection prospects with NASA's POEMMA mission.

## Contribution

It provides the strongest lower bounds on the lifetime of super-heavy dark matter particles based on cosmic ray data and evaluates future detection capabilities.

## Key findings

- No ultra-high-energy cosmic ray events observed beyond 10^{11.3} GeV.
- Derived the strongest lower limit on SHDM particle lifetime.
- Assessed POEMMA's potential to detect SHDM signals.

## Abstract

In 15 years of data taking the Pierre Auger Observatory has observed no events beyond $10^{11.3}$ GeV. This null result translates into an upper bound on the flux of ultrahigh-energy cosmic rays implying $J (> 10^{11.3}$ GeV) $< 3.6 \times 10^{-5}$ km$^{-2}$ sr$^{-1}$ yr$^{-1}$, at the 90\%C.L. We interpret this bound as a constraint on extreme-energy photons originating in the decay super-heavy dark matter (SHDM) particles clustered in the Galactic halo. Armed with this constraint we derive the strongest lower limit on the lifetime of hadronically decaying SHDM particles with masses in the range, $10^{14} < M_X/ $ GeV $< 10^{15}$. We also explore the capability of future NASA's POEMMA mission to search for SHDM signals.