Related papers: High Energy Thresholds in SUSY GUTs - A refined an…
The idea of reduction of couplings consists in searching for renormalization group invariant relations between parameters of a renormalizable theory that hold to all orders of perturbation theory. Based on the principle of the reduction of…
We revisit proton decay via the color-triplet Higgs multiplets in the minimal supersymmetric grand unified model with heavy sfermions. Although the model has been believed to be excluded due to the too short lifetime of proton, we have…
We study $3$rd family Yukawa unification in the context of supersymmetric (SUSY) $\mathrm{SO}(10)$ GUTs and $\mathrm{SO}(10)$-motivated boundary conditions for the SUSY-breaking soft terms. We consider $\mu<0$ such that the SUSY…
We revisit the minimal Nambu-Goldstone (NG) Higgs supersymmetric (SUSY) SU(5) grand unified model and study its phenomenological implications. The Higgs sector of the model possesses a global SU(6) symmetry, which is spontaneously broken…
This report is a review of the present status of GUT, especially renormalizable minimal SO(10) GUT, and its future prospect. It consists of two parts. In part I, I review how the minimal renormalizable supersymmetric SO(10) GUT, an SO(10)…
A D-parity violated SUSY SU(4) x SU(2) _ L x SU(2)_R gauge model with the Higgs sector 2{(4,1,2)+(4-bar,1, 2)}+(1,2,2)+some(1,1,1)'s is shown to have the following advantages: (i) It is the simplest and almost unique solution that satisfies…
In the supersymmetric grand unified theories (SUSY GUTs), gauge bosons associated with the unified gauge group induce proton decay. We investigate the proton decay rate via the gauge bosons in the SUSY GUTs under the two situations; one is…
We present a bottom-up approach to the question of supersymmetry breaking in the MSSM. Starting with the experimentally measurable low-energy supersymmetry breaking parameters, which can take any values consistent with present experimental…
We investigate the prospects to achieve unification of the gauge couplings in models without supersymmetry. We restrict our discussion to $SU(5), SO(10)$ and $E_6$ models that mimic the structure of the Standard Model as much as possible…
We construct lists of supersymmetric models with extended gauge groups at intermediate steps, all of which are based on SO(10) unification. We consider three different kinds of setups: (i) The model has exactly one additional intermediate…
A Higgs boson mass $\sim 126$ GeV as determined by the LHC data requires a large loop correction which in turn implies a large sfermion mass. Implication of this result for the stability of the proton in supersymmetric grand unified…
We report on a preferred region of supersymmetric parameter space by t, b, tau Yukawa unification. We find a narrow region survives for mu > 0 (suggested by b --> s gamma and the anomalous magnetic moment of the muon) with A_0 \sim - 2…
We survey some recent ideas and progress in looking for particle physics beyond the Standard Model, connected by the theme of Supersymmetry (SUSY). We review the success of SUSY-GUT models, the expected experimental signatures and present…
Finite Unified Theories (FUTs) are N=1 supersymmetric Grand Unified Theories that can be made all-loop finite. The requirement of all-loop finiteness leads to a severe reduction of the free parameters of the theory and, in turn, to a large…
Coherent analyses at future LHC and LC experiments can be used to explore the breaking mechanism of supersymmetry and to reconstruct the fundamental theory at high energies, in particular at the grand unification scale. This will be…
Going beyond the theta function approximation we discuss supersymmetric unification of gauge couplings with exact decoupling of light and heavy particles at energy scales below their masses. We find that the Minimal SUSY model is strongly…
We have studied the reconstruction of supersymmetric theories at high scales by evolving the fundamental parameters from the electroweak scale upwards. Universal minimal supergravity and gauge mediated supersymmetry breaking have been taken…
The lack of evidence for superparticles at the CERN LHC, along with the rather high value of the Higgs mass, has sharpened the perception that supersymmetric model parameter space is highly electroweak fine-tuned (EWFT). We compare three…
The recent discovery of a 125 GeV Higgs-like resonance at LHC, coupled with the lack of evidence for weak scale supersymmetry (SUSY), have severely constrained SUSY models such as mSUGRA/CMSSM. As LHC probes deeper into SUSY model parameter…
The minimal supersymmetric SO(10) model, in which not only the gauge but also the third generation fermion Yukawa couplings are unified, provides a simple and highly predictive theoretical scenario for the understanding of the origin of the…