Kinetic mixing, dark photons and extra dimensions. Part II: fermionic dark matter
| Autor: | T.G. Rizzo |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Nuclear and High Energy Physics Particle physics 010308 nuclear & particles physics Physics beyond the Standard Model Phenomenology of Large extra dimensions Dark matter FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Decoupling (cosmology) 01 natural sciences Dark photon Standard Model High Energy Physics - Phenomenology Extra dimensions Higgs field MAJORANA High Energy Physics - Phenomenology (hep-ph) Phenomenology of Field Theories in Higher Dimensions 0103 physical sciences lcsh:QC770-798 lcsh:Nuclear and particle physics. Atomic energy. Radioactivity 010306 general physics |
| Zdroj: | Journal of High Energy Physics Journal of High Energy Physics, Vol 2018, Iss 10, Pp 1-29 (2018) |
| ISSN: | 1029-8479 |
| DOI: | 10.1007/jhep10(2018)069 |
| Popis: | Extra dimensions can be very useful tools when constructing new physics models. Previously, we began investigating toy models for the 5-D analog of the kinetic mixing/vector portal scenario where the interactions of bulk dark matter with the brane-localized fields of the Standard Model are mediated by a massive $U(1)_D$ dark photon also living in the bulk. In that setup, where the dark matter was taken to be a complex scalar, a number of nice features were obtained such as $U(1)_D$ breaking by boundary conditions without the introduction of a dark Higgs field, the absence of potentially troublesome SM Higgs-dark singlet mixing, also by boundary conditions, the natural similarity of the dark matter and dark photon masses and the decoupling of the heavy gauge Kaluza-Klein states from the Standard Model. In the present paper we extend this approach by examining the more complex cases of Dirac and Majorana fermionic dark matter. In particular, we discuss a new mechanism that can occur in 5-D (but not in 4-D) that allows for light Dirac dark matter in the $\sim 100$ MeV mass range, even though it has an $s$-wave annihilation into Standard Model fields, by avoiding the strong constraints that arise from both the CMB and 21 cm data. This mechanism makes use of the presence of the Kaluza-Klein excitations of the dark photon to extremize the increase in the annihilation cross section usually obtained via resonant enhancement. In the Majorana dark matter case, we explore the possibility of a direct $s$-channel dark matter pair-annihilation process producing the observed relic density, due to the general presence of parity-violating dark matter interactions, without employing the usual co-annihilation mechanism which is naturally suppressed in this 5-D setup. Comment: 22 pages, 7 Figs; discussions and refs. added, typos fixed; title changed to match earlier work |
| Databáze: | OpenAIRE |
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