A multi-temperature universe can allow a sub-MeV dark photon dark matter

Abstract An analysis of sub-MeV dark photon as dark matter is given which is achieved with two hidden sectors, one of which interacts directly with the visible sector while the second has only indirect coupling with the visible sector. The formalism for the evolution of three bath temperatures for the visible sector and the two hidden sectors is developed and utilized in solution of Boltzmann equations coupling the three sectors. We present exclusion plots where the sub-MeV dark photon can be dark matter. The analysis can be extended to a multi-temperature universe with multiple hidden sectors and multiple heat baths.

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Chiral composite asymmetric dark matter

Journal of High Energy Physics ◽

10.1007/jhep07(2021)220 ◽

2021 ◽

Vol 2021 (7) ◽

Author(s):

Masahiro Ibe ◽

Shin Kobayashi ◽

Keiichi Watanabe

Keyword(s):

Dark Matter ◽

Flavor Symmetry ◽

Dark Sector ◽

Coincidence Problem ◽

Dark Photon ◽

The Standard Model ◽

Visible Sector ◽

Dynamical Breaking ◽

Asymmetric Dark Matter ◽

The Masses

Abstract The asymmetric dark matter (ADM) scenario solves the baryon-dark matter coincidence problem when the dark matter (DM) mass is of $$ \mathcal{O}(1) $$ O 1 GeV. Composite ADM models based on QCD-like strong dynamics are particularly motivated since the strong dynamics naturally provides the DM mass of $$ \mathcal{O}(1) $$ O 1 GeV and the large annihilation cross-section simultaneously. In those models, the sub-GeV dark photon often plays an essential role in transferring the excessive entropy in the dark sector into the visible sector, i.e., the Standard Model sector. This paper constructs a chiral composite ADM model where the U(1)D gauge symmetry is embedded into the chiral flavor symmetry. Due to the dynamical breaking of the chiral flavor symmetry, the model naturally provides the masses of the dark photon and the dark pions in the sub-GeV range, both of which play crucial roles for a successful ADM model.

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A cosmologically consistent millicharged dark matter solution to the EDGES anomaly of possible string theory origin

Journal of High Energy Physics ◽

10.1007/jhep12(2021)148 ◽

2021 ◽

Vol 2021 (12) ◽

Author(s):

Amin Aboubrahim ◽

Pran Nath ◽

Zhu-Yao Wang

Keyword(s):

Dark Matter ◽

Particle Physics ◽

Evolution Equations ◽

Dirac Fermions ◽

Absorption Signal ◽

Hidden Sector ◽

Coupled Equations ◽

Dark Photon ◽

Visible Sector ◽

Physics Model

Abstract Analysis of EDGES data shows an absorption signal of the redshifted 21-cm line of atomic hydrogen at z ∼ 17 which is stronger than expected from the standard ΛCDM model. The absorption signal interpreted as brightness temperature T21 of the 21-cm line gives an amplitude of $$ -{500}_{-500}^{+200} $$ − 500 − 500 + 200 mK at 99% C.L. which is a 3.8σ deviation from what the standard ΛCDM cosmology gives. We present a particle physics model for the baryon cooling where a fraction of the dark matter resides in the hidden sector with a U(1) gauge symmetry and a Stueckelberg mechanism operates mixing the visible and the hidden sectors with the hidden sector consisting of dark Dirac fermions and dark photons. The Stueckelberg mass mixing mechanism automatically generates a millicharge for the hidden sector dark fermions providing a theoretical basis for using millicharged dark matter to produce the desired cooling of baryons seen by EDGES by scattering from millicharged dark matter. We compute the relic density of the millicharged dark matter by solving a set of coupled equations for the dark fermion and dark photon yields and for the temperature ratio of the hidden sector and the visible sector heat baths. For the analysis of baryon cooling, we analyze the evolution equations for the temperatures of baryons and millicharged dark matter as a function of the redshift. We exhibit regions of the parameter space which allow consistency with the EDGES data. We note that the Stueckelberg mechanism arises naturally in strings and the existence of a millicharge would point to its string origin.

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Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

Journal of High Energy Physics ◽

10.1007/jhep02(2021)229 ◽

2021 ◽

Vol 2021 (2) ◽

Author(s):

Amin Aboubrahim ◽

Michael Klasen ◽

Pran Nath

Keyword(s):

Dark Matter ◽

Particle Physics ◽

Small Mass ◽

Big Bang ◽

Mass Splitting ◽

Recoil Energy ◽

Dirac Fermions ◽

Dark Sector ◽

Dark Photon ◽

Physics Model

Abstract We present a particle physics model to explain the observed enhancement in the Xenon-1T data at an electron recoil energy of 2.5 keV. The model is based on a U(1) extension of the Standard Model where the dark sector consists of two essentially mass degenerate Dirac fermions in the sub-GeV region with a small mass splitting interacting with a dark photon. The dark photon is unstable and decays before the big bang nucleosynthesis, which leads to the dark matter constituted of two essentially mass degenerate Dirac fermions. The Xenon-1T excess is computed via the inelastic exothermic scattering of the heavier dark fermion from a bound electron in xenon to the lighter dark fermion producing the observed excess events in the recoil electron energy. The model can be tested with further data from Xenon-1T and in future experiments such as SuperCDMS.

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Dark photon dark matter in the presence of inhomogeneous structure

Journal of High Energy Physics ◽

10.1007/jhep06(2020)132 ◽

2020 ◽

Vol 2020 (6) ◽

Cited By ~ 5

Author(s):

Samuel J. Witte ◽

Salvador Rosauro-Alcaraz ◽

Samuel D. McDermott ◽

Vivian Poulin

Keyword(s):

Dark Matter ◽

Inhomogeneous Structure ◽

Dark Photon

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Kinetic mixing, dark photons and extra dimensions. Part III. Brane localized dark matter

Journal of High Energy Physics ◽

10.1007/jhep03(2021)173 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

Thomas G. Rizzo ◽

George N. Wojcik

Keyword(s):

Dark Matter ◽

Extra Dimensions ◽

Model Building ◽

New Physics ◽

Model Complexity ◽

Complex Scalar ◽

Dark Photon ◽

Complex Models ◽

The Cost ◽

D Model

Abstract Extra dimensions have proven to be a very useful tool in constructing new physics models. In earlier work, we began investigating toy models for the 5-D analog of the kinetic mixing/vector portal scenario where the interactions of dark matter, taken to be, e.g., a complex scalar, with the brane-localized fields of the Standard Model (SM) are mediated by a massive U(1)D dark photon living in the bulk. These models were shown to have many novel features differentiating them from their 4-D analogs and which, in several cases, avoided some well-known 4-D model building constraints. However, these gains were obtained at the cost of the introduction of a fair amount of model complexity, e.g., dark matter Kaluza-Klein excitations. In the present paper, we consider an alternative setup wherein the dark matter and the dark Higgs, responsible for U(1)D breaking, are both localized to the ‘dark’ brane at the opposite end of the 5-D interval from where the SM fields are located with only the dark photon now being a 5-D field. The phenomenology of such a setup is explored for both flat and warped extra dimensions and compared to the previous more complex models.

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Extension of Standard Model in multi-spinor field formalism — Visible and dark sectors

International Journal of Modern Physics A ◽

10.1142/s0217751x16300271 ◽

2016 ◽

Vol 31 (18) ◽

pp. 1630027

Author(s):

Ikuo S. Sogami

Keyword(s):

Dark Matter ◽

Standard Model ◽

Dark Sector ◽

Quadratic Interaction ◽

Inflationary Phase ◽

The Standard Model ◽

Visible Sector ◽

Field Formalism ◽

Main Component ◽

Higgs Fields

With multi-spinor fields which behave as triple-tensor products of the Dirac spinors, the Standard Model is extended so as to embrace three families of ordinary quarks and leptons in the visible sector and an additional family of exotic quarks and leptons in the dark sector of our Universe. Apart from the gauge and Higgs fields of the Standard Model symmetry G, new gauge and Higgs fields of a symmetry isomorphic to G are postulated to exist in the dark sector. It is the bi-quadratic interaction between visible and dark Higgs fields that opens a main portal to the dark sector. Breakdowns of the visible and dark electroweak symmetries result in the Higgs boson with mass 125 GeV and a new boson which can be related to the diphoton excess around 750 GeV. Subsequent to a common inflationary phase and a reheating period, the visible and dark sectors follow weakly-interacting paths of thermal histories. We propose scenarios for dark matter in which no dark nuclear reaction takes place. A candidate for the main component of the dark matter is a stable dark hadron with spin 3/2, and the upper limit of its mass is estimated to be 15.1 GeV/c2.

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Astrophysical aspects of milli-charged dark matter in a Higgs–Stueckelberg model

Modern Physics Letters A ◽

10.1142/s0217732315500893 ◽

2015 ◽

Vol 30 (18) ◽

pp. 1550089 ◽

Cited By ~ 2

Author(s):

A. L. dos Santos ◽

D. Hadjimichef

Keyword(s):

Dark Matter ◽

Weakly Interacting Massive Particles ◽

Dark Sector ◽

Minimal Coupling ◽

Astrophysical Application ◽

Gauge Sector ◽

Dark Photon ◽

The Standard Model ◽

Vector Bosons ◽

The Impact

An extension of the Standard Model (SM) is studied, in which two new vector bosons are introduced, a first boson Z' coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson A' field, in the dark sector of the model, remains massless and originates a dark photon γ'. A hybrid mixing scenario is considered based on a combined Higgs and Stueckelberg mechanisms. In a Compton-like process, a photon scattered by a weakly interacting massive particles (WIMP) is converted into a dark photon. This process is studied, in an astrophysical application obtaining an estimate of the impact on stellar cooling of white dwarfs and neutron stars.

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