Do you want to publish a course? Click here

Multicomponent dark matter particles in a two-loop neutrino model

362   0   0.0 ( 0 )
 Added by Hiroshi Okada
 Publication date 2013
  fields
and research's language is English




Ask ChatGPT about the research

We construct a loop induced seesaw model in a TeV scale theory with gauged U(1)_{B-L} symmetry. Light neutrino masses are generated at two-loop level and right-handed neutrinos also obtain their masses by one-loop effect. Multi-component Dark Matters (DMs) are included in our model due to the remnant discrete symmetry after the B-L symmetry breaking and the Z_2 parity which is originally imposed to the model. We investigate the multi-component DM properties, in which we have two fermionic DMs with different mass scales, O(10) GeV and O(100-1000) GeV. The former mass corresponds to the lightest right-handed neutrino mass induced by the loop effect, although the latter one to the SM gauge singlet fermion. We show each of the DM annihilation processes and compare to the the observation of relic abundance, together with the constraints of Lepton Flavor Violation (LFV) and active neutrino masses. Moreover we show that our model has some parameter region allowed by the direct detection result reported by XENON100, and it is possible to verify the model by the future XENON experiment.



rate research

Read More

We study a two loop induced seesaw model with global $U(1)_{B-L}$ symmetry, in which we consider two component dark matter particles. The dark matter properties are investigated together with some phenomenological constraints such as electroweak precision test, neutrino masses and mixing and lepton flavor violation. In particular, the mixing angle between the Standard Model like Higgs and an extra Higgs is extremely restricted by the direct detection experiment of dark matter. We also discuss the contribution of Goldstone boson to the effective number of neutrino species $Delta N_{rm eff}approx0.39$ which has been reported by several experiments.
We propose a model in which the origin of neutrino mass is dependent on the existence of dark matter. Neutrinos acquire mass at the three-loop level and the dark matter is the neutral component of a fermion triplet. We show that experimental constraints are satisfied and that the dark matter can be tested in future direct-detection experiments. Furthermore, the model predicts a charged scalar that can be within reach of collider experiments like the LHC.
We study scenarios where loop processes give the dominant contributions to dark matter decay or annihilation despite the presence of tree level channels. We illustrate this possibility in a specific model where dark matter is part of a hidden sector that communicates with the Standard Model sector via a heavy neutrino portal. We explain the underpinning rationale for how loop processes mediated by the portal neutrinos can parametrically dominate over tree level decay channels, and demonstrate that this qualitatively changes the indirect detection signals in positrons, neutrinos, and gamma rays.
We discuss radiative seesaw models, in which an exact $Z_2times Z_2$ symmetry is imposed. Due to the exact $Z_2times Z_2$ symmetry, neutrino masses are generated at a two-loop level and at least two extra stable electrically neutral particles are predicted. We consider two models: one has a multi-component dark matter system and the other one has a dark radiation in addition to a dark matter. In the multi-component dark matter system, non-standard dark matter annihilation processes exist. We find that they play important roles in determining the relic abundance and also responsible for the monochromatic neutrino lines resulting from the dark matter annihilation process. In the model with the dark radiation, the structure of the Yukawa coupling is considerably constrained and gives an interesting relationship among cosmology, lepton flavor violating decay of the charged leptons and the decay of the inert Higgs bosons.
We analyze the effects of introducing vector-like leptons in the Higgs Triplet Model providing the lightest vector-like neutrino as a Dark Matter candidate. We explore the effect of the relic density constraint on the mass and Yukawa coupling of dark matter, as well as calculate the cross sections for indirect and direct dark matter detection. We show our model predictions for the neutrino and muon fluxes from the Sun, and the restrictions they impose on the parameter space. We show that this model, with a restricted parameter space, is completely consistent with dark matter constraints, and indicate the resulting mass region for the dark matter.
comments
Fetching comments Fetching comments
Sign in to be able to follow your search criteria
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا