scholarly journals Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun

2011 ◽  
Vol 84 (3) ◽  
Author(s):  
M. Ajello ◽  
W. B. Atwood ◽  
L. Baldini ◽  
G. Barbiellini ◽  
D. Bastieri ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
High Energy ◽  
The Sun

Mass limits for dark-matter particles derived from high-energy neutrinos from the Sun

1991 ◽  
Vol 44 (8) ◽  
pp. 2220-2240 ◽  
Author(s):  
N. Sato ◽  
K. S. Hirata ◽  
T. Kajita ◽  
T. Kifune ◽  
K. Kihara ◽  
...  
Keyword(s):  
Dark Matter ◽  
High Energy ◽  
The Sun ◽  
High Energy Neutrinos

Detectors for cosmic particles, neutrinos and exotic matter

2020 ◽  
pp. 655-710
Author(s):  
Hermann Kolanoski ◽  
Norbert Wermes
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Cosmic Radiation ◽  
Charged Particles ◽  
Cosmic Ray ◽  
High Energy ◽  
Detection Methods ◽  
Astroparticle Physics ◽  
High Energy Cosmic Rays ◽  
Cosmic Origin

Astroparticle physics deals with the investigation of cosmic radiation using similar detection methods as in particle physics, however, mostly with quite different detector arrangements. In this chapter the detection principles for the different radiation types with cosmic origin are presented, this includes charged particles, gamma radiation, neutrinos and possibly existing Dark Matter. In the case of neutrinos also experiments at accelerators and reactors are included. Examples, which are typical for the different areas, are given for detectors and their properties. For cosmic ray detection apparatuses are deployed above the atmosphere with balloons or satellites or on the ground using the atmosphere as calorimeter in which high-energy cosmic rays develop showers or in underground areas including in water and ice.

scholarly journals Quasielastic Lepton Scattering off Two-Component Dark Matter in Hypercolor Model

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 708 ◽  
Author(s):  
Vitaly Beylin ◽  
Maxim Bezuglov ◽  
Vladimir Kuksa ◽  
Egor Tretiakov
Keyword(s):  
Dark Matter ◽  
Total Cross Section ◽  
Cross Section ◽  
Strong Dependence ◽  
Cosmic Ray ◽  
High Energy ◽  
Dominant Contribution ◽  
Quasielastic Scattering ◽  
Two Component ◽  
The Cross

The interaction of high-energy leptons with components of Dark Matter in a hypercolor model is considered. The possibility of detection, using IceCube secondary neutrinos produced by quasielastic scattering of cosmic ray electrons off hidden mass particles, is investigated. The dominant contribution to the cross section results from diagrams with scalar exchanges. A strong dependence of the total cross section on the Dark Matter components mass is also found.

scholarly journals Impact of Cosmic-Ray Physics on Dark Matter Indirect Searches

2018 ◽  
Vol 2018 ◽  
pp. 1-23 ◽  
Author(s):  
Daniele Gaggero ◽  
Mauro Valli
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
High Energy ◽  
Research Field ◽  
Current Data ◽  
Weakly Interacting Massive Particles ◽  
Beyond The Standard Model ◽  
High Energy Astrophysics ◽  
Classical Plasma ◽  
Galactic Cosmic Ray

The quest for the elusive dark matter (DM) that permeates the Universe (and in general the search for signatures of physics beyond the Standard Model at astronomical scales) provides a unique opportunity and a tough challenge to the high energy astrophysics community. In particular, the so-called DMindirect searches—mostly focused on a class of theoretically well-motivated DM candidates such as the weakly interacting massive particles—are affected by a complex astrophysical background of cosmic radiation. The understanding and modeling of such background require a deep comprehension of an intricate classical plasma physics problem, i.e., the interaction between high energy charged particles, accelerated in peculiar astrophysical environments, and magnetohydrodynamic turbulence in the interstellar medium of our galaxy. In this review we highlight several aspects of this exciting interplay between the most recent claims of DM annihilation/decay signatures from the sky and the galactic cosmic-ray research field. Our purpose is to further stimulate the debate about viable astrophysical explanations, discussing possible directions that would help breaking degeneracy patterns in the interpretation of current data. We eventually aim to emphasize how a deep knowledge on the physics of CR transport is therefore required to tackle the DM indirect search program at present and in the forthcoming years.

scholarly journals Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow

2020 ◽  
Vol 633 ◽  
pp. A83
Author(s):  
J. Becker Tjus ◽  
P. Desiati ◽  
N. Döpper ◽  
H. Fichtner ◽  
J. Kleimann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Solar Cycle ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Cosmic Ray ◽  
High Energy ◽  
High Solar Activity ◽  
The Sun ◽  
Theoretical Understanding

The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiments, such as Argo-YBJ, Tibet, HAWC, and IceCube. Most notably, the shadow’s size and depth was recently shown to correlate with the 11-year solar cycle. The interpretation of such measurements, which help to bridge the gap between solar physics and high-energy particle astrophysics, requires a solid theoretical understanding of cosmic-ray propagation in the coronal magnetic field. It is the aim of this paper to establish theoretical predictions for the cosmic-ray Sun shadow in order to identify observables that can be used to study this link in more detail. To determine the cosmic-ray Sun shadow, we numerically compute trajectories of charged cosmic rays in the energy range of 5−316 TeV for five different mass numbers. We present and analyze the resulting shadow images for protons and iron, as well as for typically measured cosmic-ray compositions. We confirm the observationally established correlation between the magnitude of the shadowing effect and both the mean sunspot number and the polarity of the magnetic field during the solar cycle. We also show that during low solar activity, the Sun’s shadow behaves similarly to that of a dipole, for which we find a non-monotonous dependence on energy. In particular, the shadow can become significantly more pronounced than the geometrical disk expected for a totally unmagnetized Sun. For times of high solar activity, we instead predict the shadow to depend monotonously on energy and to be generally weaker than the geometrical shadow for all tested energies. These effects should become visible in energy-resolved measurements of the Sun shadow, and may in the future become an independent measure for the level of disorder in the solar magnetic field.

scholarly journals High-energy positrons and gamma radiation from decaying constituents of a two-component dark atom model

2015 ◽  
Vol 24 (13) ◽  
pp. 1545004 ◽  
Author(s):  
K. Belotsky ◽  
M. Khlopov ◽  
C. Kouvaris ◽  
M. Laletin
Keyword(s):  
Dark Matter ◽  
Massive Particle ◽  
Cosmic Ray ◽  
High Energy ◽  
Photon Flux ◽  
Dark Matter Candidate ◽  
Small Range ◽  
State Radiation ◽  
Two Component ◽  
Doubly Charged

We study a two-component dark matter candidate inspired by the minimal walking technicolor (WTC) model. Dark matter consists of a dominant strongly interactive massive particle (SIMP)-like dark atom component made of bound states between primordial helium nuclei and a doubly charged technilepton and a small WIMP-like component made of another dark atom bound state between a doubly charged technibaryon and a technilepton. This scenario is consistent with direct search experimental findings because the dominant SIMP component interacts too strongly to reach the depths of current detectors with sufficient energy to recoil and the WIMP-like component is too small to cause significant amount of events. In this context, a metastable technibaryon that decays to [Formula: see text], [Formula: see text] and [Formula: see text] can, in principle, explain the observed positron excess by AMS-02 and PAMELA, while being consistent with the photon flux observed by FERMI/LAT. We scan the parameters of the model and we find the best possible fit to the latest experimental data. We find that there is a small range of parameter space that this scenario can be realized under certain conditions regarding the cosmic ray propagation and the final state radiation (FSR). This range of parameters fall inside the region where the current run of large hadron collider (LHC) can probe, and therefore it will soon be possible to either verify or exclude conclusively this model of dark matter.

scholarly journals Search for dark matter cosmic-ray electrons and positrons from the Sun with the Fermi Large Area Telescope

2020 ◽  
Vol 101 (2) ◽  
Author(s):  
A. Cuoco ◽  
P. De La Torre Luque ◽  
F. Gargano ◽  
M. Gustafsson ◽  
F. Loparco ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
The Sun ◽  
Large Area ◽  
Electrons And Positrons

scholarly journals The pinching method for Galactic cosmic ray positrons: Implications in the light of precision measurements

2017 ◽  
Vol 605 ◽  
pp. A17 ◽  
Author(s):  
M. Boudaud ◽  
E. F. Bueno ◽  
S. Caroff ◽  
Y. Genolini ◽  
V. Poulin ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
High Energy ◽  
Transport Processes ◽  
Secondary Component ◽  
Dark Matter Annihilation ◽  
Propagation Parameters ◽  
Positron Flux ◽  
Galactic Cosmic Ray ◽  
Best Fit

Context. Two years ago, the Ams-02 collaboration released the most precise measurement of the cosmic ray positron flux. In the conventional approach, in which positrons are considered as purely secondary particles, the theoretical predictions fall way below the data above 10 GeV. One suggested explanation for this anomaly is the annihilation of dark matter particles, the so-called weakly interactive massive particles (WIMPs), into standard model particles. Most analyses have focused on the high-energy part of the positron spectrum, where the anomaly lies, disregarding the complicated GeV low-energy region where Galactic cosmic ray transport is more difficult to model and solar modulation comes into play. Aims. Given the high quality of the latest measurements by Ams-02, it is now possible to systematically re-examine the positron anomaly over the entire energy range, this time taking into account transport processes so far neglected, such as Galactic convection or diffusive re-acceleration. These might impact somewhat on the high-energy positron flux so that a complete and systematic estimate of the secondary component must be performed and compared to the Ams-02 measurements. The flux yielded by WIMPs also needs to be re-calculated more accurately to explore how dark matter might source the positron excess. Methods. We devise a new semi-analytical method to take into account transport processes thus far neglected, but important below a few GeV. It is essentially based on the pinching of inverse Compton and synchrotron energy losses from the magnetic halo, where they take place, inside the Galactic disc. The corresponding energy loss rate is artificially enhanced by the so-called pinching factor, which needs to be calculated at each energy. We have checked that this approach reproduces the results of the Green function method at the per mille level. This new tool is fast and allows one to carry out extensive scans over the cosmic ray propagation parameters. Results. We derive the positron flux from sub-GeV to TeV energies for both gas spallation and dark matter annihilation. We carry out a scan over the cosmic ray propagation parameters, which we strongly constrain by requiring that the secondary component does not overshoot the Ams-02 measurements. We find that only models with large diffusion coefficients are selected by this test. We then add to the secondary component the positron flux yielded by dark matter annihilation. We carry out a scan over WIMP mass to fit the annihilation cross-section and branching ratios, successively exploring the cases of a typical beyond-the-standard-model WIMP and an annihilation through light mediators. In the former case, the best fit yields a p-value of 0.4% for a WIMP mass of 264 GeV, a value that does not allow to reproduce the highest energy data points. If we require the mass to be larger than 500 GeV, the best-fit χ2 per degree of freedom always exceeds a value of 3. The case of light mediators is even worse, with a best-fit χ2 per degree of freedom always larger than 15. Conclusions. We explicitly show that the cosmic ray positron flux is a powerful and independent probe of Galactic cosmic ray propagation. It should be used as a complementary observable to other tracers such as the boron-to-carbon ratio. This analysis shows also that the pure dark matter interpretation of the positron excess is strongly disfavoured. This conclusion is based solely on the positron data, and no other observation, such as the antiproton flux or the CMB anisotropies, needs to be invoked.

scholarly journals Astroparticle Physics with H.E.S.S.: recents results and nearfuture prospects

2019 ◽  
Vol 209 ◽  
pp. 01054
Author(s):  
Emmanuel Moulin
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Lorentz Invariance ◽  
Cosmic Ray ◽  
High Energy ◽  
New Physics ◽  
Galactic Centre ◽  
Astroparticle Physics ◽  
Dark Matter Search ◽  
Physics Program

H.E.S.S. is an array of five Imaging Atmospheric Cherenkov Telescopes located in Namibia. It is designed for observations of astrophysical sources emitting very-high-energy (VHE) gamma rays in the energy range from a few ten GeVs to several ten TeVs. The H.E.S.S. instrument consists of four identical 12 m diameter telescopes and a 28 m diameter telescope placed at the center of the array. An ambitious Astroparticle Physics program is being carried out by the H.E.S.S. collaboration searching for New Physics in the VHE gamma-ray sky. The program includes the search for WIMP dark matter and axion-like particles, tests of Lorentz invariance, cosmic-ray electron measurements, and search for intergalactic magnetic fields. I will present the latest results on dark matter search from the observations of the Galactic Centre region, the search for Lorentz invariance violation with the 2014 flare observation of Markarian 501, and the first measurement of the cosmic-ray electron spectrum up to 20 TeV. The future of the H.E.S.S. Astroparticle Physics program will be discussed.

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