scholarly journals Sensitivity of cosmic-ray experiments to ultrahigh-energy photons: Reconstruction of the spectrum and limits on the superheavy dark matter

2009 ◽  
Vol 80 (10) ◽  
Author(s):  
O. E. Kalashev ◽  
G. I. Rubtsov ◽  
S. V. Troitsky
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
Ultrahigh Energy ◽  
Superheavy Dark Matter

scholarly journals Superheavy dark matter and ultrahigh-energy cosmic rays

2006 ◽  
Vol 84 (6-7) ◽  
pp. 537-543
Author(s):  
R Dick ◽  
K M Hopp ◽  
K E Wunderle
Keyword(s):  
Dark Matter ◽  
Cosmic Rays ◽  
Early Universe ◽  
Cosmic Ray ◽  
Pierre Auger Observatory ◽  
Ultrahigh Energy ◽  
Mass Window ◽  
Ultrahigh Energy Cosmic Rays ◽  
Superheavy Dark Matter ◽  
Arrival Directions

The phase of inflationary expansion in the early Universe produces superheavy relics in a mass window between 1012 and 1014 GeV. Decay or annihilation of these superheavy relics an explain the observed ultrahigh-energy cosmic rays beyond the Greisen–Zatsepin–Kuzmin cutoff. We emphasize that the pattern of cosmic-ray arrival directions seen by the Pierre Auger observatory will decide between the different proposals for the origin of ultrahigh-energy cosmic rays.PACS Nos.: 98.70.Sa, 98.70.–f, 95.35.+d, 14.80.–j

scholarly journals Direct measurement of upward-going ultrahigh energy dark matter at the Pierre Auger Observatory

2021 ◽  
Author(s):  
Ye Xu
Keyword(s):  
Dark Matter ◽  
Energy Range ◽  
Pierre Auger Observatory ◽  
Ultrahigh Energy ◽  
Extensive Air Shower ◽  
Air Shower ◽  
The Earth ◽  
Pass Through ◽  
Incoming Energy ◽  
Superheavy Dark Matter

Abstract It is assumed that two types of dark matter particles exist: superheavy dark matter particles (SHDM), the mass of which ∼ inflaton mass, and light fermion dark matter (DM) particles, which are the ultrahigh energy (UHE) products of the decay of SHDM. The Earth will be taken as a detector to search for the UHE DM particles directly. These upward-going particles, which pass through the Earth and air and interact with nuclei, can be detected by the fluorescence detectors (FD) of the Pierre Auger Observatory (Auger), via fluorescent photons due to the development of an extensive air shower. The numbers and fluxes of expected UHE DM particles are evaluated in the incoming energy range between 1 EeV and 1 ZeV with the different lifetimes of decay of SHDM and mass of Z′. According to the Auger data from 2008 to 2019, the upper limit for UHE DM fluxes is also estimated at 90% confidence limit with the FD of Auger. Finally, it is reasonable to make a conclusion that UHE DM particles could be directly detected in the energy range between O(1 EeV) and O(10 EeV) with the FD of Auger. This might prove whether SHDM particles exist in the Universe.

scholarly journals Present and future status of light dark matter models from cosmic-ray electron upscattering

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
James B. Dent ◽  
Bhaskar Dutta ◽  
Jayden L. Newstead ◽  
Ian M. Shoemaker ◽  
Natalia Tapia Arellano
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
Future Status

An excess radio signal in the Abell 4038 cluster

2020 ◽  
Vol 500 (4) ◽  
pp. 5583-5588
Author(s):  
Man Ho Chan ◽  
Chak Man Lee
Keyword(s):  
Dark Matter ◽  
Spectral Data ◽  
Cross Section ◽  
Radio Signal ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Radio Continuum ◽  
Test Statistic ◽  
Dark Matter Annihilation

ABSTRACT In the past decade, various instruments, such as the Large Area Telescope (LAT) on the Fermi Gamma Ray Space Telescope, the Alpha Magnetic Spectrometer (AMS) and the Dark Matter Particle Explorer(DAMPE), have been used to detect the signals of annihilating dark matter in our Galaxy. Although some excesses of gamma rays, antiprotons and electrons/positrons have been reported and are claimed to be dark matter signals, the uncertainties of the contributions of Galactic pulsars are still too large to confirm the claims. In this paper, we report on a possible radio signal of annihilating dark matter manifested in the archival radio continuum spectral data of the Abell 4038 cluster. By assuming a thermal annihilation cross-section and comparing the dark matter annihilation model with the null hypothesis (cosmic ray emission without dark matter annihilation), we obtain very large test statistic (TS) values, TS > 45, for four popular annihilation channels, which correspond to more than 6σ statistical preference. This reveals a possible potential signal of annihilating dark matter. In particular, our results are also consistent with the recent claims of dark matter mass, m ≈ 30–50 GeV, annihilating via the $\rm b\bar{b}$ quark channel with the thermal annihilation cross-section. However, at this time, we cannot exclude the possibility that a better background cosmic ray model could explain the spectral data without recourse to dark matter annihilations.

scholarly journals A possible radio signal of annihilating dark matter in the Abell 4038 cluster

2019 ◽  
Vol 495 (1) ◽  
pp. L124-L128 ◽  
Author(s):  
Man Ho Chan ◽  
Chak Man Lee
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Radio Signal ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Radio Continuum ◽  
Test Statistic ◽  
Large Area ◽  
Dark Matter Annihilation

ABSTRACT In the past decade, some telescopes [e.g. Fermi-Large Area Telescope (LAT), Alpha Magnetic Spectrometer(AMS), and Dark Matter Particle Explorer(DAMPE)] were launched to detect the signals of annihilating dark matter in our Galaxy. Although some excess of gamma-rays, antiprotons, and electrons/positrons have been reported and claimed as dark matter signals, the uncertainties of Galactic pulsars’ contributions are still too large to confirm the claims. In this Letter, we report a possible radio signal of annihilating dark matter manifested in the archival radio continuum spectral data of the Abell 4038 cluster. By assuming the thermal annihilation cross-section and comparing the dark matter annihilation model with the null hypothesis (cosmic ray emission without dark matter annihilation), we get very large test statistic values >45 for four popular annihilation channels, which correspond to more than 6.5σ statistical preference. This provides a very strong evidence for the existence of annihilating dark matter. In particular, our results also support the recent claims of dark matter mass m ≈ 30–50 GeV annihilating via the bb̄ quark channel with the thermal annihilation cross-section.

scholarly journals Testing Lorentz invariance with the ultrahigh energy cosmic ray spectrum

2009 ◽  
Vol 79 (8) ◽  
Author(s):  
Xiao-Jun Bi ◽  
Zhen Cao ◽  
Ye Li ◽  
Qiang Yuan
Keyword(s):  
Lorentz Invariance ◽  
Cosmic Ray ◽  
Ultrahigh Energy

scholarly journals Cosmic-Ray Signatures of Dark Matter Decay

2010 ◽  
Author(s):  
David Tran ◽  
George Alverson ◽  
Pran Nath ◽  
Brent Nelson
Keyword(s):  
Dark Matter ◽  
Cosmic Ray
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