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Dark Energy and Dark Matter, Mirror World and E_6 Unification

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 Added by Chitta Ranjan Das
 Publication date 2007
  fields Physics
and research's language is English




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In the present talk we have developed a concept of parallel ordinary (O) and mirror (M) worlds. We have shown that in the case of a broken mirror parity (MP), the evolutions of fine structure constants in the O- and M-worlds are not identical. It is assumed that E_6-unification inspired by superstring theory restores the broken MP at the scale sim 10^{18} GeV, what unavoidably leads to the different E_6-breakdowns at this scale: E_6 to SO(10)times U(1)_Z - in the O-world, and E_6 to SU(6)times SU(2)_Z - in the M-world. Considering only asymptotically free theories, we have presented the running of all the inverse gauge constants alpha_i^{-1} in the one-loop approximation. Then a `quintessence scenario is discussed for the model of accelerating universe. Such a scenario is related with an axion (`acceleron) of a new gauge group SU(2)_Z which has a coupling constant g_Z extremely growing at the scale Lambda_Zsim 10^{-3} eV.

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181 - R. Foot 2007
A mirror sector of particles and forces provides a simple explanation of the inferred dark matter of the Universe. The status of this theory is reviewed - with emphasis on how the theory explains the impressive DAMA/NaI annual modulation signal, whilst also being consistent with the null results of the other direct detection experiments.
Dark photons and mirror matter are well-motivated dark matter candidates. It is possible that both of them arose during the compactification and symmetry breaking scenario of the heterotic $E_8times E_8$ string theory and are related to each other. In this case, dark photons can become a natural portal into the mirror world. Unfortunately, the expected magnitude of the induced interactions of ordinary matter with mirror matter is too small to be of phenomenological interest.
We discuss the possibility to predict the QCD axion mass in the context of grand unified theories. We investigate the implementation of the DFSZ mechanism in the context of renormalizable SU(5) theories. In the simplest theory, the axion mass can be predicted with good precision in the range $m_a = (2-16)$ neV, and there is a strong correlation between the predictions for the axion mass and proton decay rates. In this context, we predict an upper bound for the proton decay channels with antineutrinos, $tau(pto K^+ bar{ u}) lesssim 4 times 10^{37} text{ yr}$ and $tau(p to pi^+ bar{ u}) lesssim 2 times 10^{36}text{ yr}$. This theory can be considered as the minimal realistic grand unified theory with the DFSZ mechanism and it can be fully tested by proton decay and axion experiments.
In the present paper we have developed a concept of parallel ordinary (O) and mirror (M) worlds. We have shown that in the case of a broken mirror parity (MP), the evolutions of fine structure constants in the O- and M-worlds are not identical. It is assumed that E_6-unification inspired by superstring theory restores the broken MP at the scale sim 10^{18} GeV, what unavoidably leads to the different E_6-breakdowns at this scale: E_6 to SO(10)times U(1)_Z - in the O-world, and E_6 to SU(6)times SU(2)_Z - in the M-world. Considering only asymptotically free theories, we have presented the running of all the inverse gauge constants alpha_i^{-1} in the one-loop approximation. Then a `quintessence scenario is discussed for our model of accelerating universe. Such a scenario is related with an axion (`acceleron) of a new gauge group SU(2)_Z which has a coupling constant g_Z extremely growing at the scale Lambda_Zsim 10^{-3} eV.
Gauge coupling unification and the success of TeV-scale weakly interacting dark matter are usually taken as evidence of low energy supersymmetry (SUSY). However, if we assume that the tuning of the higgs can be explained in some unnatural way, from environmental considerations for example, SUSY is no longer a necessary component of any Beyond the Standard Model theory. In this paper we study the minimal model with a dark matter candidate and gauge coupling unification. This consists of the SM plus fermions with the quantum numbers of SUSY higgsinos, and a singlet. It predicts thermal dark matter with a mass that can range from 100 GeV to around 2 TeV and generically gives rise to an electric dipole moment that is just beyond current experimental limits, with a large portion of its allowed parameter space accessible to next generation EDM and direct detection experiments. We study precision unification in this model by embedding it in a 5-D orbifold GUT where certain large threshold corrections are calculable, achieving gauge coupling and b-tau unification, and predicting a rate of proton decay just beyond current limits.
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