arXiv subjects

Tetsuro Yoshida

Publications and source records attributed to Tetsuro Yoshida.

3 recordsLinked to original sources

arXiv2010

Neutrino masses and $μ$ terms in a supersymmetric extra U(1) model

We propose a supersymmetric extra U(1) model, which can generate small neutrino masses and necessary $μ$ terms, simultaneously. Fields including quarks and leptons are embedded in three ${\bf 27}$s of $E_6$ in a different way among generations. The model has an extra U(1) gauge symmetry at TeV regions, which has discriminating features from other models studied previously. Since a neutrino mass matrix induced in the model has a constrained texture with limited parameters, it can give a prediction. If we impose neutrino oscillation data to fix those parameters, a value of $\sinθ_{13}$ can be determined. We also discuss several phenomenological features which are discriminated from the ones of the MSSM.

hep-ph↗

arXiv2010

Enhancement of the annihilation of dark matter in a radiative seesaw model

The radiative seesaw model with an inert doublet has been shown to be attractive from a viewpoint of both neutrino masses and cold dark matter. However, if we apply this model to the explanation of the positron excess in the cosmic ray observed by PAMELA, a huge boost factor is required although it can be automatically explained that no anti-proton excess has been observed there. We consider an extension of the model to enhance the thermally averaged annihilation cross section without changing the features of the model favored by both the neutrino oscillation and the relic abundance of dark matter. It is shown that the data of PAMELA and Fermi-LAT can be well explained in this extended model. Constraints from gamma ray observations are also discussed.

hep-ph↗

arXiv2009

Reconciliation of CDM abundance and $μ\to eγ$ in a radiative seesaw model

We reexamine relic abundance of a singlet fermion as a CDM candidate, which contributes to the neutrino mass generation through radiative seesaw mechanism. We search solutions for Yukawa couplings and the mass spectrum of relevant fields to explain neutrino oscillation data. For such solutions, we show that an abundance of a lightest singlet fermion can be consistent with WMAP data without conflicting with both bounds of $μ\to eγ$ and $τ\to μγ$. This reconciliation does not need any modification of the original radiative seesaw model other than by specifying flavor structure of Yukawa couplings and taking account of coannihilation effects.

hep-ph↗