arXiv subjects

Yuichi Chikira

Publications and source records attributed to Yuichi Chikira.

3 recordsLinked to original sources

arXiv2000

Natural Mass Hierarchy of Z Boson and Scalar Top in No-Scale Supergravity

It is studied that `no-scale' model makes hierarchy between scalar top mass and Z boson mass naturally. The supersymmetry breaking parameters are constrained by flavor changing neutral currents in minimal supersymmetric standard model. One of the solution of the problem is that gaugino mass is the only source of the supersymmetry breaking parameters at Planck scale. However, in such scenario, we need a cancellation between Higgs mass parameters in minimization condition of the Higgs potential. We insist that there is no such cancellation in no-scale model, and that the no-scale model gives us the prediction of scalar top mass and lightest Higgs mass. The lightest Higgs mass is predicted as $m_H = 110 \pm 5 $ GeV.

hep-ph↗

arXiv1998

The Singular Seesaw Mechanism with Hierarchical Dirac Neutrino Mass

The singular seesaw mechanism can naturally explain the atmospheric neutrino deficit by the maximal oscillation between $ν_{μ_L}$ and $ν_{μ_R}$. This mechanism can also induce three different scales of neutrino mass squared differences, which can explain the neutrino deficits of three independent experiments (solar, atmospheric, and LSND) by neutrino oscillations. In this paper we show that the realistic mixing angles among neutrinos can be obtained by introducing the hierarchy in the Dirac neutrino mass. In the case where Majorana neutrino mass matrix has rank 2, the solar neutrino deficit is explained by the vacuum oscillation between $ν_e$ and $ν_τ$. We also consider the case where Majorana neutrino mass matrix has rank 1. In this case, the mater enhanced Mikheyev-Smirnov-Wolfenstein solar neutrino solution is prefered as the solution of the solar neutrino deficit.

hep-ph↗

arXiv1998

The Sliding Singlet Mechanism with Gauge Mediated Supersymmetry Breaking

The sliding singlet mechanism is one of the most interesting solutions of the triplet-doublet splitting problem. We analyze this mechanism in the gauge mediated supersymmetry breaking scenario. We show that the sliding singlet mechanism does not work in the naive gauge mediation scenario because of the singlet linear terms derived from the gravity, although $F$ term is much smaller than the one in the gravity mediation scenario. We also consider the extension in order for the sliding singlet mechanism to work.

hep-ph↗