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 Sensitivity of future linear $$\hbox {e}^+\hbox {e}^-$$ colliders to processes of dark matter production with light mediator exchange

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Jan Kalinowski ◽  
Wojciech Kotlarski ◽  
Krzysztof Mȩkała ◽  
Paweł Sopicki ◽  
Aleksander Filip Żarnecki
Keyword(s):  
Dark Matter ◽  
Linear Collider ◽  
Production Cross ◽  
Photon Emission ◽  
International Linear Collider ◽  
High Energy ◽  
Initial State ◽  
Final State ◽  
State Radiation ◽  
Wide Range

AbstractAs any $$e^+e^-$$ e + e - scattering process can be accompanied by a hard photon emission from the initial state radiation, the analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with an invisible final state. Thus high energy $$e^+e^-$$ e + e - colliders offer a unique possibility for the most general search of dark matter (DM) based on the mono-photon signature. We consider production of DM particles at the International Linear Collider (ILC) and Compact Linear Collider (CLIC) experiments via a light mediator exchange. Detector effects are taken into account within the Delphes fast simulation framework. Limits on the light DM production in a simplified model are set as a function of the mediator mass and width based on the expected two-dimensional distributions of the reconstructed mono-photon events. The experimental sensitivity is extracted in terms of the DM production cross section. Limits on the mediator couplings are then presented for a wide range of mediator masses and widths. For light mediators, for masses up to the centre-of-mass energy of the collider, coupling limits derived from the mono-photon analysis are more stringent than those expected from direct resonance searches in decay channels to SM particles.

scholarly journals Gamma-ray line from electroweakly interacting non-abelian spin-1 dark matter

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Tomohiro Abe ◽  
Motoko Fujiwara ◽  
Junji Hisano ◽  
Kohei Matsushita
Keyword(s):  
Dark Matter ◽  
Cross Sections ◽  
Line Search ◽  
Gamma Ray ◽  
Galactic Center ◽  
Photon Emission ◽  
Strong Constraint ◽  
Wave States ◽  
Sommerfeld Enhancement ◽  
The Masses

Abstract We study gamma-ray line signatures from electroweakly interacting non-abelian spin-1 dark matter (DM). In this model, Z2-odd spin-1 particles including a DM candidate have the SU(2)L triplet-like features, and the Sommerfeld enhancement is relevant in the annihilation processes. We derive the annihilation cross sections contributing to the photon emission and compare with the SU(2)L triplet fermions, such as Wino DM in the supersymmetric Standard Model. The Sommerfeld enhancement factor is approximately the same in both systems, while our spin-1 DM predicts the larger annihilation cross sections into γγ/Zγ modes than those of the Wino by $$ \frac{38}{9} $$ 38 9 . This is because a spin-1 DM pair forms not only J = 0 but also J = 2 partial wave states where J denotes the total spin angular momentum. Our spin-1 DM also has a new annihilation mode into Z2-even extra heavy vector and photon, Z′γ. For this mode, the photon energy depends on the masses of DM and the heavy vector, and thus we have a chance to probe the mass spectrum. The latest gamma-ray line search in the Galactic Center region gives a strong constraint on our spin-1 DM. We can probe the DM mass for ≲ 25.3 TeV by the Cherenkov Telescope Array experiment even if we assume a conservative DM density profile.

scholarly journals Observational Constraints of 30–40 GeV Dark Matter Annihilation in Galaxy Clusters

2016 ◽  
Vol 2016 ◽  
pp. 1-4
Author(s):  
Man Ho Chan
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Cross Section ◽  
Upper Bound ◽  
Gamma Ray ◽  
Galactic Center ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Dark Matter Annihilation ◽  
The One

Recently, it has been shown that the annihilation of 30–40 GeV dark matter particles through bb- channel can satisfactorily explain the excess GeV gamma-ray spectrum near the Galactic Center. In this paper, we apply the above model to galaxy clusters and use the latest upper limits of gamma-ray flux derived from Fermi-LAT data to obtain an upper bound of the annihilation cross section of dark matter. By considering the extended density profiles and the cosmic ray profile models of 49 galaxy clusters, the upper bound of the annihilation cross section can be further tightened to σv≤9×10-26 cm3 s−1. This result is consistent with the one obtained from the data near the Galactic Center.

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.

scholarly journals Measurement of the e+e−→π+π−π0π0 cross section using initial-state radiation at BABAR

2017 ◽  
Vol 96 (9) ◽  
Author(s):  
J. P. Lees ◽  
V. Poireau ◽  
V. Tisserand ◽  
E. Grauges ◽  
A. Palano ◽  
...  
Keyword(s):  
Cross Section ◽  
Initial State Radiation ◽  
Initial State ◽  
State Radiation
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