scholarly journals Gamma-ray signatures for Kaluza-Klein dark matter

2006 ◽  
Author(s):  
Lars Bergström ◽  
Torsten Bringmann ◽  
Michael Gustafsson ◽  
Martin Eriksson
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Kaluza Klein

scholarly journals From diffuse extragalactic and galactic gamma-rays to limits on extra dimensions

2019 ◽  
Vol 492 (1) ◽  
pp. L66-L68
Author(s):  
Michel Cassé ◽  
Bruno Mansoulié ◽  
Joseph Silk
Keyword(s):  
Dark Matter ◽  
Gamma Rays ◽  
Extra Dimensions ◽  
Gamma Ray ◽  
Core Collapse ◽  
Planck Mass ◽  
Galactic Emission ◽  
Lower Limits ◽  
Kaluza Klein

ABSTRACT We derive the maximum fraction of energy emitted in the form of massive (Kaluza–Klein) gravitons by core collapse supernovae, and the corresponding minimal extra-dimensional Planck mass M* in the ADD gravity framework at TeV scales. Our constraints arise (a) from the extragalactic gamma-ray background observed by Fermi-LAT after astrophysical sources have been removed and (b) via the residual galactic emission left after astrophysical and potentially dark matter emission have been removed. We focus on a number of extra dimensions 3 and 4, since M* is then in the TeV range, where astrophysical and collider constraints compete. Lower limits on M* are derived in the case (a) of 8.0 and 1.1 TeV for n = 3 and n = 4, respectively, and in the case (b) of 16 and 1.9 TeV. These limits are especially robust and insensitive to the various uncertainties involved.

scholarly journals The gamma-ray spectral feature from Kaluza–Klein dark matter annihilation and its observability

2017 ◽  
Vol 27 (01) ◽  
pp. 1750187 ◽  
Author(s):  
Satoshi Tsuchida ◽  
Masaki Mori
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Galactic Halo ◽  
Spectral Feature ◽  
High Energy ◽  
Dark Matter Annihilation ◽  
Peak Structure ◽  
Boost Factor ◽  
Near Future ◽  
Kaluza Klein

The theory of universal extra dimensions involves Kaluza–Klein (KK) particles. The lightest KK particle (LKP) is one of the good candidates for cold dark matter. Annihilation of LKP dark matter in the Galactic halo produces high-energy gamma-rays. The gamma-ray spectrum shows a characteristic peak structure around the LKP mass. This paper investigates the observability of this peak structure by near-future detectors taking account of their energy resolution and calculates the expected energy spectrum of the gamma-ray signal. Then, by using the High-Energy Stereoscopic System (HESS) data, we set some constraints on the boost factor, which is a product of the annihilation cross-section relative to the thermal one and an uncertain factor dependent on the substructure of the LKP distribution in the Galactic halo, for each LKP mass. The resulting upper limit on the boost factor is in the range from 1 to 30. The constraints can be regarded as comparable with the results of previous work for gamma-ray and electron–positron observation. However, the observational data for the TeV or higher energy region are still limited, and the possible LKP signal is not conclusive. Thus, we expect near-future missions with better sensitivity will clarify whether the LKP dark matter should exist or not.

scholarly journals Spin-one dark matter and gamma ray signals from the galactic center

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
H. Hernández-Arellano ◽  
M. Napsuciale ◽  
S. Rodríguez
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Gamma Ray ◽  
Galactic Center ◽  
Photon Emission ◽  
Scalar Coupling ◽  
Initial State ◽  
Internal Bremsstrahlung ◽  
Resonance Effects ◽  
State Radiation

Abstract In this work we study the possibility that the gamma ray excess (GRE) at the Milky Way galactic center come from the annihilation of dark matter with a (1, 0) ⊕ (0, 1) space-time structure (spin-one dark matter, SODM). We calculate the production of prompt photons from initial state radiation, internal bremsstrahlung, final state radiation including the emission from the decay products of the μ, τ or hadronization of quarks. Next we study the delayed photon emission from the inverse Compton scattering (ICS) of electrons (produced directly or in the prompt decay of μ, τ leptons or in the hadronization of quarks produced in the annihilation of SODM) with the cosmic microwave background or starlight. All these mechanisms yield significant contributions only for Higgs resonant exchange, i.e. for M ≈ MH /2, and the results depend on the Higgs scalar coupling to SODM, gs. The dominant mechanism at the GRE bump is the prompt photon production in the hadronization of b quarks produced in $$ \overline{D}D\to \overline{b}b $$ D ¯ D → b ¯ b , whereas the delayed photon emission from the ICS of electrons coming from the hadronization of b quarks produced in the same reaction dominates at low energies (ω < 0.3 GeV ) and prompt photons from c and τ , as well as from internal bremsstrahlung, yield competitive contributions at the end point of the spectrum (ω ≥ 30 GeV ). Taking into account all these contributions, our results for photons produced in the annihilation of SODM are in good agreement with the GRE data for gs ∈ [0.98, 1.01] × 10−3 and M ∈ [62.470, 62.505] GeV . We study the consistency of the corresponding results for the dark matter relic density, the spin-independent dark matter-nucleon cross-section σp and the cross section for the annihilation of dark matter into $$ \overline{b}b $$ b ¯ b , τ+τ−, μ+μ− and γγ, taking into account the Higgs resonance effects, finding consistent results in all cases.

scholarly journals Effective field theory analysis of dark matter-standard model interactions with spin one mediators

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Fabiola Fortuna ◽  
Pablo Roig ◽  
José Wudka
Keyword(s):  
Field Theory ◽  
Dark Matter ◽  
Standard Model ◽  
Effective Field Theory ◽  
Gamma Ray ◽  
Direct Detection ◽  
Effective Field ◽  
Indirect Detection ◽  
Theory Analysis ◽  
Invisible Decay

Abstract We analyze interactions between dark matter and standard model particles with spin one mediators in an effective field theory framework. In this paper, we are considering dark particles masses in the range from a few MeV to the mass of the Z boson. We use bounds from different experiments: Z invisible decay width, relic density, direct detection experiments, and indirect detection limits from the search of gamma-ray emissions and positron fluxes. We obtain solutions corresponding to operators with antisymmetric tensor mediators that fulfill all those requirements within our approach.

scholarly journals On a Possible Origin of the Gamma-ray Excess around the Galactic Center

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1432
Author(s):  
Dmitry O. Chernyshov ◽  
Andrei E. Egorov ◽  
Vladimir A. Dogiel ◽  
Alexei V. Ivlev
Keyword(s):  
Dark Matter ◽  
Gamma Rays ◽  
Molecular Clouds ◽  
Alternative Explanation ◽  
Gamma Ray ◽  
Galactic Center ◽  
The Self ◽  
Large Area ◽  
Mhd Turbulence ◽  
The Standard Model

Recent observations of gamma rays with the Fermi Large Area Telescope (LAT) in the direction of the inner galaxy revealed a mysterious excess of GeV. Its intensity is significantly above predictions of the standard model of cosmic rays (CRs) generation and propagation with a peak in the spectrum around a few GeV. Popular interpretations of this excess are that it is due to either spherically distributed annihilating dark matter (DM) or an abnormal population of millisecond pulsars. We suggest an alternative explanation of the excess through the CR interactions with molecular clouds in the Galactic Center (GC) region. We assumed that the excess could be imitated by the emission of molecular clouds with depleted density of CRs with energies below ∼10 GeV inside. A novelty of our work is in detailed elaboration of the depletion mechanism of CRs with the mentioned energies through the “barrier” near the cloud edge formed by the self-excited MHD turbulence. This depletion of CRs inside the clouds may be a reason for the deficit of gamma rays from the Central Molecular Zone (CMZ) at energies below a few GeV. This in turn changes the ratio between various emission components at those energies and may potentially absorb the GeV excess by a simple renormalization of key components.

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