scholarly journals Spectral analysis of the gamma-ray background near the dwarf Milky Way satellite Segue 1: Improved limits on the cross section of neutralino dark matter annihilation

2012 ◽  
Vol 86 (6) ◽  
Author(s):  
A. N. Baushev ◽  
S. Federici ◽  
M. Pohl
Keyword(s):  
Dark Matter ◽  
Spectral Analysis ◽  
Cross Section ◽  
Milky Way ◽  
Gamma Ray ◽  
Dark Matter Annihilation ◽  
The Cross

scholarly journals Relieving Tensions Related to the Dark Matter Interpretation of the Fermi-LAT Data

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 92
Author(s):  
Man Chan
Keyword(s):  
Dark Matter ◽  
Synchrotron Radiation ◽  
Milky Way ◽  
Gamma Ray ◽  
Feedback Process ◽  
Dark Matter Annihilation ◽  
Dwarf Spheroidal Galaxies ◽  
Matter Model ◽  
Consistent Picture ◽  
Dark Matter Model

Recently, many studies indicate that the GeV gamma ray excess signal from the central Milky Way can be best explained by ∼40–50 GeV dark matter annihilating via the b b ¯ channel. However, this model appears to be disfavored by the recent Fermi-LAT data for dwarf spheroidal galaxies and the constraint from synchrotron radiation. In this article, we describe a consistent picture to relieve the tensions between the dark matter annihilation model and the observations. We show that a baryonic feedback process is the key to alleviate the tensions and the ∼40–50 GeV dark matter model is still the best one to account for the GeV gamma ray excess in the Milky Way.

scholarly journals Constraints to Dark Matter Annihilation from High-Latitude HAWC Unidentified Sources

Galaxies ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Javier Coronado-Blázquez ◽  
Miguel A. Sánchez-Conde
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Gamma Rays ◽  
High Latitude ◽  
Gamma Ray ◽  
Detection Threshold ◽  
Dark Matter Annihilation ◽  
Annihilation Channel ◽  
Dark Matter Search ◽  
Spatially Extended

The Λ CDM cosmological framework predicts the existence of thousands of subhalos in our own Galaxy not massive enough to retain baryons and become visible. Yet, some of them may outshine in gamma rays provided that the dark matter is made of weakly interacting massive particles (WIMPs), which would self-annihilate and would appear as unidentified gamma-ray sources (unIDs) in gamma-ray catalogs. Indeed, unIDs have proven to be competitive targets for dark matter searches with gamma rays. In this work, we focus on the three high-latitude ( | b | ≥ 10 ) sources present in the 2HWC catalog of the High Altitude Water Cherenkov (HAWC) observatory with no clear associations at other wavelengths. Indeed, only one of these sources, 2HWC J1040+308, is found to be above the HAWC detection threshold when considering 760 days of data, i.e., a factor 1.5 more exposure time than in the original 2HWC catalog. Other gamma-ray instruments, such as Fermi-LAT or VERITAS at lower energies, do not detect the source. Also, this unID is reported as spatially extended, making it even more interesting in a dark matter search context. While waiting for more data that may shed further light on the nature of this source, we set competitive upper limits on the annihilation cross section by comparing this HAWC unID to expectations based on state-of-the-art N-body cosmological simulations of the Galactic subhalo population. We find these constraints to be particularly competitive for heavy WIMPs, i.e., masses above ∼25 (40) TeV in the case of the b b ¯ ( τ + τ − ) annihilation channel, reaching velocity-averaged cross section values of 2 × 10 − 25 ( 5 × 10 − 25 ) cm 3 ·s − 1 . Although far from testing the thermal relic cross section value, the obtained limits are independent and nicely complementary to those from radically different DM analyses and targets, demonstrating once again the high potential of this DM search approach.

scholarly journals A Dark Matter WIMP That Can Be Detected and Definitively Identified with Currently Planned Experiments

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 270
Author(s):  
Caden LaFontaine ◽  
Bailey Tallman ◽  
Spencer Ellis ◽  
Trevor Croteau ◽  
Brandon Torres ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Cross Sections ◽  
Direct Detection ◽  
Vector Boson ◽  
Massive Particle ◽  
Current Evidence ◽  
Channel Cross Section ◽  
Dark Matter Annihilation ◽  
The Cross

A recently proposed dark matter WIMP (weakly interacting massive particle) has only second-order couplings to gauge bosons and itself. As a result, it has small annihilation, scattering, and creation cross-sections, and is consequently consistent with all current experiments and the observed abundance of dark matter. These cross-sections are, however, still sufficiently large to enable detection in experiments that are planned for the near future, and definitive identification in experiments proposed on a longer time scale. The (multi-channel) cross-section for annihilation is consistent with thermal production and freeze-out in the early universe, and with current evidence for dark matter annihilation in analyses of the observations of gamma rays by Fermi-LAT and antiprotons by AMS-02, as well as the constraints from Planck and Fermi-LAT. The cross-section for direct detection via collision with xenon nuclei is estimated to be slightly below 10−47 cm2, which should be attainable by LZ and Xenon nT and well within the reach of Darwin. The cross-section for collider detection via vector boson fusion is estimated to be ∼1 fb, and may be ultimately attainable by the high-luminosity LHC; definitive collider identification will probably require the more powerful facilities now being proposed.

CONSTRAINING DARK MATTER ANNIHILATION WITH NEUTRINOS AND GAMMA RAYS

2011 ◽  
Vol 01 ◽  
pp. 245-251
Author(s):  
NICOLE F. BELL
Keyword(s):  
Dark Matter ◽  
Total Cross Section ◽  
Cross Section ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Mass Range ◽  
Dark Matter Halo ◽  
Dark Matter Annihilation ◽  
Upper Limits ◽  
Wide Range

We examine dark matter annihilation in galaxy halos. By considering annihilation into all Standard Model particles we show that the least detectable final states, namely neutrinos, define a strong general upper bound on the total cross section. This limit is much stronger than the unitarity bound in the most interesting mass range and implies annihilation cannot significantly modify dark matter halo density profiles. We also calculate conservative upper limits on the self-annihilation cross section to monoenergetic gamma rays over a wide range of dark matter masses, using gamma-ray data from the Milky Way, Andromeda (M31), and the cosmic background. We compare gamma-ray-based and neutrino-based upper limits on the total cross section.

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