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تسجيل مستخدم جديدDark photon portal into mirror world
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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.
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The understanding of the origin of dark matter has great importance for cosmology and particle physics. Several interesting extensions of the standard model dealing with solution of this problem motivate the concept of hidden sectors consisting of SU
(3)xSU(2)_LxU(1)_Y singlet fields. Among these models, the mirror matter model is certainly one of the most interesting. The model explains the origin of parity violation in weak interactions, it could also explain the baryon asymmetry of the Universe and provide a natural ground for the explanation of dark matter. The mirror matter could have a portal to our world through photon-mirror photon mixing (epsilon). This mixing would lead to orthopositronium (o-Ps) to mirror orthopositronium oscillations, the experimental signature of which is the apparently invisible decay of o-Ps. In this paper, we describe an experiment to search for the decay o-Ps -> invisible in vacuum by using a pulsed slow positron beam and a massive 4pi BGO crystal calorimeter. The developed high efficiency positron tagging system, the low calorimeter energy threshold and high hermiticity allow the expected sensitivity in mixing strength to be epsilon about 10^-9, which is more than one order of magnitude below the current Big Bang Nucleosynthesis limit and in a region of parameter space of great theoretical and phenomenological interest. The vacuum experiment with such sensitivity is particularly timely in light of the recent DAMA/LIBRA observations of the annual modulation signal consistent with a mirror type dark matter interpretation.
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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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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.
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