Revisiting ultrahigh-energy constraints on decaying super-heavy dark matter

Abstract

We revisit constraints on decaying very heavy dark matter (VHDM) using the latest ultrahigh-energy cosmic-ray (UHECR; $E\gtrsim 10^{18}$ eV) data and ultrahigh-energy (UHE) $\gamma$-ray flux upper limits, measured by the Pierre Auger Observatory. We present updated limits on the VHDM lifetime (${\tau }_{\chi }$) for masses up to $\sim 10^{15}$~GeV, considering decay into quarks, leptons, and massive bosons. In particular, we consider not only the UHECR spectrum but their composition data that favors heavier nuclei. Such a combined analysis improves the limits at $\lesssim 10^{12}$ GeV because VHDM decay does not produce UHECR nuclei. We also show that the constraints from the UHE $\gamma$-ray upper limits are $\sim 10$ more stringent than that obtained from cosmic rays, for all of the Standard Model final states we consider. The latter improves our limits to VHDM lifetime by a factor of two for dark matter mass $\gtrsim 10^{12}$ GeV.

9 pages, 5 figures, Accepted for publication in PRD

References in corpus (13)

• Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory: Measurements at Energies above 10^17.8 eV
• Search for dark matter annihilations towards the inner Galactic halo from 10 years of observations with H.E.S.S
• Constraints on the Galactic Halo Dark Matter from Fermi-LAT Diffuse Measurements
• Measurement of the cosmic-ray energy spectrum above $2.5\times 10^{18}$ eV using the Pierre Auger Observatory
• Neutrino Constraints on the Dark Matter Total Annihilation Cross Section
• Features of the energy spectrum of cosmic rays above $2.5\times 10^{18}$ eV using the Pierre Auger Observatory
• Absorption of Very High Energy Gamma Rays in the Milky Way
• Constraining Very Heavy Dark Matter Using Diffuse Backgrounds of Neutrinos and Cascaded Gamma Rays
• A new view on Auger data and cosmogenic neutrinos in light of different nuclear disintegration and air-shower models
• Constraints on decaying dark matter from the extragalactic gamma-ray background
• Model-independent dark matter annihilation bound from the diffuse gamma ray flux
• KASCADE-Grande Limits on the Isotropic Diffuse Gamma-Ray Flux between 100 TeV and 1 EeV
• Multi-Messenger Physics with the Pierre Auger Observatory