Mixed dark matter in Universal Extra Dimension models with TeV scale WR and Z'

Journal of High Energy Physics (Impact Factor: 5.62). 01/2006; 12(12):067-067. DOI: 10.1088/1126-6708/2006/12/067
Source: arXiv

ABSTRACT We show that in a class of universal extra dimension (UED) models that solves both the neutrino mass and proton decay problems using low scale left-right symmetry, the dark matter of the Universe consists of an admixture of KK photon and KK right-handed neutrinos. We present a full calculation of the dark matter density in these models taking into account the co-annihilation effects due to near by states such as the scalar partner of the KK photon as well as fermion states near the right-handed KK neutrino. Using the value of the relic CDM density, we obtain upper limits on R-1 of about 400-650 GeV and MZ'

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    ABSTRACT: Relic abundance of dark matter is investigated in the framework of universal extra dimension models with right-handed neutrinos. These models are free from the serious Kaluza-Klein (KK) graviton problem that the original universal extra dimension model has. The first KK particle of the right-handed neutrino is a candidate for dark matter in this framework, and its relic abundance is determined by three processes, (1) the decay of the KK photon into the first KK right-handed neutrino in the late universe, (2) production of the first KK right-handed neutrino from the thermal bath in the early universe, and (3) the decay of higher KK right-handed neutrinos into the first KK right-handed neutrino in the late universe. When ordinary neutrino masses are large enough such as the degenerate mass spectrum case, the last process contribute to the abundance significantly, even if the reheating temperature is low. The scale of the extra dimension consistent with cosmological observations can be 500 GeV in the minimal setup of universal extra dimension models with right-handed neutrinos.

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