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arXiv · 2302.02993

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

Saikat Das·Kohta Murase·Toshihiro Fujii
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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 $\sim10^{15}$~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 $\sim10$ 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 $\gtrsim10^{12}$ GeV.

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Saikat Das, Kohta Murase, Toshihiro Fujii. 2023-02-06. Revisiting ultrahigh-energy constraints on decaying super-heavy dark matter. https://doi.org/10.1103/physrevd.107.103013

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