GAMMA-RAY CONSTRAINTS ON DECAYING DARK MATTER

2010 ◽  
Vol 25 (11n12) ◽  
pp. 969-975
Author(s):  
CHUAN-REN CHEN ◽  
SOURAV K. MANDAL ◽  
FUMINOBU TAKAHASHI
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Hadronic Decay ◽  
Total Flux ◽  
Final States ◽  
Final State ◽  
Positron Fraction ◽  
Decaying Dark Matter

The anomalies in positron fraction observed in PAMELA and total flux of electrons and positron reported by Fermi can be explained by a decaying dark matter. The agreement between astrophysical background and observed data in anti-proton indicates a lep-tophilic dark matter and constrains the hadronic decay branching ratios. In this work, we study the constrains on decaying rates of a dark matter to various 2-body final states using the Fermi and HESS gamma-ray data. We find that µ+µ- or τ+τ- final state is preferred to simultaneously explain the excesses and meet the gamma-ray constrains.

scholarly journals Indirect effects of dark matter

2019 ◽  
Vol 28 (13) ◽  
pp. 1941011 ◽  
Author(s):  
K. M. Belotsky ◽  
E. A. Esipova ◽  
A. Kh. Kamaletdinov ◽  
E. S. Shlepkina ◽  
M. L. Solovyov
Keyword(s):  
Dark Matter ◽  
Indirect Effects ◽  
Large Scale ◽  
Gamma Ray ◽  
Space Distribution ◽  
Stable Form ◽  
Final State ◽  
Electron Positron ◽  
Text Mode ◽  
The Universe

Here, we briefly review possible indirect effects of dark matter (DM) of the universe. It includes effects in cosmic rays (CR): first of all, the positron excess at [Formula: see text]500[Formula: see text]GeV and possible electron–positron excess at 1–1.5[Formula: see text]TeV. We tell that the main and least model-dependent constraint on such possible interpretation of CR effects goes from gamma-ray background. Even ordinary [Formula: see text] mode of DM decay or annihilation produces prompt photons (FSR) so much that it leads to contradiction with data on cosmic gamma-rays. We present our attempts to possibly avoid gamma-ray constraint. They concern with peculiarities of both space distribution of DM and their physics. The latter involves complications of decay/annihilation modes of DM, modifications of Lagrangian of DM-ordinary matter interaction and inclusion of mode with identical fermions in final state. In this way, no possibilities to suppress were found except, possibly, the mode with identical fermions. While the case of spatial distribution variation allows achieving consistency between different data. Also, we consider stable form of DM which can interact with baryons. We show which constraint such DM candidate can get from the damping effect in plasma during large-scale structure (LSS) formation in comparison with other existing constraints.

scholarly journals High-energy cosmic antiparticle excess vs. isotropic gamma-ray background problem in decaying dark matter Universe

2016 ◽  
Vol 675 (1) ◽  
pp. 012023 ◽  
Author(s):  
V V Alekseev ◽  
K M Belotsky ◽  
Yu V Bogomolov ◽  
R I Budaev ◽  
O A Dunaeva ◽  
...  
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
High Energy ◽  
Decaying Dark Matter

scholarly journals Cosmic ray excesses from multi-component dark matter decays

2014 ◽  
Vol 29 (37) ◽  
pp. 1440003 ◽  
Author(s):  
Chao-Qiang Geng ◽  
Da Huang ◽  
Lu-Hsing Tsai
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
Parameter Range ◽  
Decay Channels ◽  
Positron Fraction ◽  
Flavor Structure ◽  
Two Component ◽  
Decaying Dark Matter ◽  
Interesting Variation ◽  
Γ Ray

We use multi-component decaying dark matter (DM) scenario to explain the possible cosmic ray excesses in the positron fraction recently confirmed by AMS-02 and the total e+ +e- flux observed by Fermi-LAT. In the two-component DM models, we find an interesting variation of the flavor structure along with the cutoff of the heavy DM. For the three-component DM case, we focus on a particular parameter range in which the best fits prefer to open only two DM decay channels with a third DM contributing nothing to the electron and positron spectra. We show that all models give the reasonable fits to both the AMS-02 positron fraction and the Fermi-LAT total e++e- flux, which are also consistent with the measured diffuse γ-ray flux by Fermi-LAT.

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