scholarly journals Measurement of cosmic ray proton spectrum with the Dark Matter Particle Explorer

2019 ◽  
Author(s):  
Chuan Yue ◽  
Antonio De Benedittis ◽  
Mario Nicola Mazziotta ◽  
Stefania Vitillo ◽  
Zhi-Hui Xu ◽  
...  
Keyword(s):  
Dark Matter ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Proton Spectrum

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 Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

2019 ◽  
Vol 5 (9) ◽  
pp. eaax3793 ◽  
Author(s):  
◽  
Q. An ◽  
R. Asfandiyarov ◽  
P. Azzarello ◽  
P. Bernardini ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Cosmic Radiation ◽  
Precise Measurement ◽  
Milky Way ◽  
Spectral Feature ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Proton Spectrum ◽  
First Time

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

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 Observation of time evolution of cosmic ray electron and positron flux with Dark Matter Particle Explorer

2019 ◽  
Author(s):  
Jingjing Zang ◽  
Yang Liu ◽  
Qiang Yuan ◽  
Chuan Yue ◽  
Keyword(s):  
Dark Matter ◽  
Time Evolution ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Positron Flux

scholarly journals Remnants of Galactic Subhalos and Their Impact on Indirect Dark-Matter Searches

Galaxies ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 65 ◽  
Author(s):  
Martin Stref ◽  
Thomas Lacroix ◽  
Julien Lavalle
Keyword(s):  
Dark Matter ◽  
Computer Simulations ◽  
Gamma Rays ◽  
Cold Dark Matter ◽  
Milky Way ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Tidal Disruption ◽  
Large Numbers ◽  
Boost Factor

Dark-matter subhalos, predicted in large numbers in the cold-dark-matter scenario, should have an impact on dark-matter-particle searches. Recent results show that tidal disruption of these objects in computer simulations is overefficient due to numerical artifacts and resolution effects. Accounting for these results, we re-estimated the subhalo abundance in the Milky Way using semianalytical techniques. In particular, we showed that the boost factor for gamma rays and cosmic-ray antiprotons is increased by roughly a factor of two.

scholarly journals DARK MATTER ANNIHILATION EXPLANATION FOR e± EXCESSES IN COSMIC RAY

2009 ◽  
Vol 24 (27) ◽  
pp. 2139-2160 ◽  
Author(s):  
XIAO-GANG HE
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Cosmic Ray ◽  
Proton Spectrum ◽  
Annihilation Rate ◽  
Dark Matter Annihilation ◽  
Data Set ◽  
Boost Factor ◽  
Physics Model ◽  
Correct Data

Recently data from PAMELA, ATIC, FERMI-LAT and HESS show that there are e± excesses in the cosmic ray energy spectrum. PAMELA shown excesses only in e+, but not in anti-proton spectrum. ATIC, FERMI-LAT and HESS shown excesses in e++e- spectrum, but the detailed shapes are different which requires future experimental observations to pin down the correct data set. Nevertheless a lot of efforts have been made to explain the observed e± excesses, and also why PAMELA only has excesses in e+ but not in anti-proton. In this brief review we discuss one of the most popular mechanisms to explain the data — the dark matter annihilation. It has long been known that about 23% of our universe is made of relic dark matter. If the relic dark matter was thermally produced, the annihilation rate is constrained resulting in the need of a large boost factor to explain the data. We will discuss in detail how a large boost factor can be obtained by the Sommerfeld and Breit–Wigner enhancement mechanisms. Some implications for particle physics model buildings will also be discussed.

scholarly journals Observations of Forbush Decreases of Cosmic-Ray Electrons and Positrons with the Dark Matter Particle Explorer

2021 ◽  
Vol 920 (2) ◽  
pp. L43
Author(s):  
Francesca Alemanno ◽  
Qi An ◽  
Philipp Azzarello ◽  
Felicia Carla Tiziana Barbato ◽  
Paolo Bernardini ◽  
...  
Keyword(s):  
Dark Matter ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Forbush Decreases ◽  
Electrons And Positrons

Dark matter particle explorer and nearby cosmic ray electron source

2015 ◽  
Vol 45 (11) ◽  
pp. 119510-119510 ◽  
Author(s):  
Lei FENG ◽  
YiZhong FAN ◽  
JianHua GUO ◽  
Jin CHANG
Keyword(s):  
Dark Matter ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Electron Source

scholarly journals Helium flux and elemental composition of galactic Cosmic Rays with the DAMPE space mission

2019 ◽  
Vol 209 ◽  
pp. 01041
Author(s):  
Margherita Di Santo
Keyword(s):  
Dark Matter ◽  
Cosmic Rays ◽  
Gamma Ray ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
High Energy ◽  
Space Mission ◽  
Galactic Cosmic Rays ◽  
Gobi Desert ◽  
Photon Spectra

DAMPE (DArk Matter Particle Explorer) is a space mission project promoted by the Chinese Academy of Sciences (CAS), in collaboration with Universities and Institutes from China, Italy and Switzerland. The detector is collecting data in a stable sun-synchronous orbit lasting 95 minutes at an altitude of about 500 km. It has been launched in December 17th, 2015, from the Jiuquan Satellite Launch Center, in the Gobi Desert. The main goals of the mission are: indirect search for Dark Matter, looking for signatures in the electron and photon spectra with energies up to 10 TeV; analysis of the flux and composition of primary Cosmic Rays with energies up to hundreds of TeV; high energy gamma-ray astronomy. Preliminary results about the Helium flux and Cosmic Ray composition will be presented and discussed.

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