Solving cosmological problem in universal extra dimension models by introducing Dirac neutrino
نویسندگان
چکیده
Universal extra dimension (UED) models with right-handed neutrinos are studied. The introduction of the neutrinos makes us possible not only to describe Dirac neutrino masses but also to solve the cosmological problem called the KK graviton problem. This problem is essentially caused by the late time decay of a KK photon into a KK graviton and a photon, and it distorts the spectrum of the cosmic microwave background or the diffuse photon. We point out that, once we introduce right-handed neutrinos to UED models, the KK photon decays dominantly into neutrinos and does not emit a photon. We also discuss sub-dominant modes with a photon in the decay quantitatively, and show that their branching ratios are so small that the spectra are not distorted. [email protected] [email protected] [email protected] [email protected]
منابع مشابه
The neutrino masses and the change of allowed parameter region in universal extra dimension models
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 KaluzaKlein (KK) graviton problem that the original universal extra dimension model possesses. The first KK particle of the right-handed neutrino is a candidate for dark matter in this framework. When ordinary neutrino masses are...
متن کاملRelic abundance of dark matter in universal extra dimension models with right-handed neutrinos
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 ...
متن کاملA universal seesaw mechanism in five dimensions
We show the universal seesaw in the extra dimension setup, where three extra vector-like fields exist in the 5D bulk with heavy masses. We take the framework of the left-right symmetric model. The universal seesaw formula is easily obtained as a replacement of the vector-like mass in 4D case Mi to 2M∗ tan[πRMi] (M∗: 5D Planck scale, Mi: vector-like bulk mass, and R: compactification radius). Th...
متن کاملCharged Higgs decays in models with singlet neutrino in large extra dimensions
In models with large extra dimensions and TeV scale quantum gravity, small (Dirac) neutrino masses can be obtained naturally if the right-handed neutrino propagates in the extra dimensions. In this scenario, with 2 Higgs doublets, we show that the decay of charged Higgs into left-handed charged lepton (say τ) and right-handed neutrino can be significantly enhanced, with O(1) branching ratio, du...
متن کاملCosmology of One Extra Dimension with Localized Gravity
We examine the cosmology of the two recently proposed scenarios for a five dimensional universe with localized gravity. We find that the scenario with a non-compact fifth dimension is potentially viable, while the scenario which might solve the hierarchy problem predicts a contracting universe, leading to a variety of cosmological problems. ∗Research fellow, Miller Institute for Basic Research ...
متن کامل