Gauge-Higgs Dark Matter (2009)
Haba, Naoyuki, Matsumoto, Shigeki, Okada, Nobuchika, Yamashita, Toshifumi
When the anti-periodic boundary condition is imposed for a bulk field in extradimensional theories, independently of the background metric, the lightest component in the anti-periodic field becomes...
Tree-level unitarity in Gauge-Higgs Unification (2009)
Haba, Naoyuki, Sakamura, Yutaka, Yamashita, Toshifumi
We numerically estimate a scale $\Lambda_{uni}$ at which tree-level unitarity is violated in the $SO(5)\times U(1)_X$ gauge-Higgs unification model by evaluating amplitudes for scattering of the...
Weak boson scattering in Gauge-Higgs Unification (2009)
Haba, Naoyuki, Sakamura, Yutaka, Yamashita, Toshifumi
The scattering amplitude for the longitudinal weak bosons is investigated in the SU(3) gauge-Higgs unification as a function of the scattering energy, the Wilson line phase \theta_H and the warp...
Borzumati, Francesca, Yamashita, Toshifumi
Flavour and CP violations that the neutrino-seesaw couplings of type I, II, III induce radiatively in the soft massive parameters of the minimal supersymmetric SU(5) model, made realistic by...
Effective Potential of Higgs Field in Warped Gauge-Higgs Unification (2008)
Haba, Naoyuki, Matsumoto, Shigeki, Okada, Nobuchika, Yamashita, Toshifumi
The gauge-Higgs unification is one of influential scenarios to solve the hierarchy problem in the Standard Model. Recently, the scenario on the warped background attracts many attentions due to a...
Effective Potential of Higgs Field in Warped Gauge-Higgs Unification (2008)
Haba, Naoyuki, Matsumoto, Shigeki, Okada, Nobuchika, Yamashita, Toshifumi
The gauge-Higgs unification is one of influential scenarios to solve the hierarchy problem in the Standard Model. Recently, the scenario on the warped background attracts many attentions due to a...
Multi-Higgs Mass Spectrum in Gauge-Higgs Unification (2008)
Kojima, Kentaro, Takenaga, Kazunori, Yamashita, Toshifumi
We study an SU(2) supersymmetric gauge model in a framework of gauge-Higgs unification. Multi-Higgs spectrum appears in the model at low energy. We develop a useful perturbative approximation scheme...
iGUT: Grand Unified Theory on Interval (2008)
Haba, Naoyuki, Sakamura, Yutaka, Yamashita, Toshifumi
We investigate a construction of five-dimensional (5D) grand unified theories (GUTs) on an interval, which we call iGUTs. We analyze supersymmetric SO(10) iGUT as an example, where the gauge...
Two loop finiteness of Higgs mass and potential in the gauge-Higgs unification (2007)
Hosotani, Yutaka, Maru, Nobuhito, Takenaga, Kazunori, Yamashita, Toshifumi
The zero mode of an extra-dimensional component of gauge potentials serves as a 4D Higgs field in the gauge-Higgs unification. We examine QED on $M^4 \times S^1$ and determine the mass and potential...
Two loop finiteness of Higgs mass and potential in the gauge-Higgs unification (2007)
Hosotani, Y., Maru, N., Takenaga, K., Yamashita, Toshifumi
The zero mode of an extra-dimensional component of gauge potentials serves as a 4D Higgs field in the gauge-Higgs unification. We examine QED on $M^4 \times S^1$ and determine the mass and potential...
Non-CKM induced flavor violation in "minimal" SUSY SU(5) models (2007)
Borzumati, Francesca, Mishima, Satoshi, Yamashita, Toshifumi
Patterns of flavor violation induced by neutrino Yukawa couplings are discussed in realistic ``minimal'' SUSY SU(5) models, obtained by adding nonrenormalizable operators to the minimal one, in order...
A novel washout effect in the flavored leptogenesis (2007)
Shindou, Tetsuo, Yamashita, Toshifumi
We investigate a flavored washout effect due to the decay of the lightest right-handed neutrino, assuming that there is non-vanishing initial lepton asymmetry and the decay of the lightest...
A novel washout effect in the flavored leptogenesis (2007)
Shindou, Tetsuo, Yamashita, Toshifumi
We investigate a flavored washout effect due to the decay of the lightest right-handed neutrino, assuming that there is non-vanishing initial lepton asymmetry and the decay of the lightest...
Itoh, Hideo, Okada, Nobuchika, Yamashita, Toshifumi
We propose a scenario of gravity mediated supersymmetry breaking (gravity mediation) in a supersymmetric Randall-Sundrum model. In our setup, both of the visible sector and the hidden sector co-exist...
Itoh, Hideo, Okada, Nobuchika, Yamashita, Toshifumi
We propose a scenario of gravity mediated supersymmetry breaking (gravity mediation) in a supersymmetric Randall-Sundrum model. In our setup, both of the visible sector and the hidden sector co-exist...
Maru, Nobuhito, Yamashita, Toshifumi
We calculate the quantum corrections to the mass of the zero mode of the fifth component of the gauge field at two-loop level in a five dimensional massless QED compactified on S^1. We discuss in...
Haba, Naoyuki, Matsumoto, Shigeki, Okada, Nobuchika, Yamashita, Toshifumi
We derive the low energy effective theory of Gauge-Higgs unification (GHU) models in the usual four dimensional framework. We find that the theories are described by only the zero-modes with a...
Maru, Nobuhito, Yamashita, Toshifumi
We calculate the quantum corrections to the mass of the zero mode of the fifth component of the gauge field at two-loop level in a five dimensional massless QED compactified on S^1. We discuss in...
Haba, Naoyuki, Matsumoto, Shigeki, Okada, Nobuchika, Yamashita, Toshifumi
We derive the low energy effective theory of Gauge-Higgs unification (GHU) models in the usual four dimensional framework. We find that the theories are described by only the zero-modes with a...
We have proposed a very attractive scenario of Grand Unified Theories (GUTs). It employs the supersymmetry (SUSY) and an anomalous U(1) symmetry whose anomaly is canceled via the Green-Schwarz...
Higgs mass in the gauge-Higgs unification (2004)
Haba, Naoyuki, Takenaga, Kazunori, Yamashita, Toshifumi
The gauge-Higgs unification theory identifies the zero mode of the extra dimensional component of the gauge field as the usual Higgs doublet. Since this degree of freedom is the Wilson line phase,...
Correct Effective Potential of Supersymmetric Yang-Mills Theory on M^4\times S^1 (2004)
Haba, Naoyuki, Takenaga, Kazunori, Yamashita, Toshifumi
We study an ${\cal N}=1$ supersymmetric Yang-Mills theory defined on $M^4\times S^1$. The vacuum expectation values for adjoint scalar field in vector multiplet, though important, has been overlooked...
Partial Gauge Symmetry Breaking via Bare Mass (2004)
Haba, Naoyuki, Takenaga, Kazunori, Yamashita, Toshifumi
We study gauge symmetry breaking patterns in supersymmetric gauge models defined on $M^4\times S^1$. Instead of utilizing the Scherk-Schwarz mechanism, supersymmetry is broken by bare mass terms for...
Horizontal symmetry in Higgs sector of GUT with U(1)_A symmetry (2004)
Maekawa, Nobuhiro, Yamashita, Toshifumi
In a series of papers, we pointed out that an anomalous $U(1)_A$ gauge symmetry naturally solves various problems in grand unified theories (GUTs) and that a horizontal gauge symmetry, $SU(2)_H$ or...
Vacuum structure in 5D SO(10) GUT on $S^1/Z_2$ (2004)
Haba, Naoyuki, Yamashita, Toshifumi
We study the vacuum structure in 5D SO(10) grand unified theory (GUT) compactified on $S^1/Z_2$ orbifold, where SO(10) is broken into $SU(3)\times SU(2)\times U(1)^2$ through the boundary conditions....
Dynamical symmetry breaking in Gauge-Higgs unification of 5D ${\mathcal N}=1$ SUSY theory (2004)
Haba, Naoyuki, Yamashita, Toshifumi
We study the dynamical symmetry breaking in the gauge-Higgs unification of the 5D ${\mathcal N}=1$ SUSY theory, compactified on an orbifold, $S^1/Z_2$. This theory identifies Wilson line degrees of...
Dynamical symmetry breaking in Gauge-Higgs unification on orbifold (2004)
Haba, Naoyuki, Hosotani, Yutaka, Kawamura, Yoshiharu, Yamashita, Toshifumi
We study the dynamical symmetry breaking in the gauge-Higgs unification of the 5D theory compactified on an orbifold, $S^1/Z_2$. This theory identifies Wilson line degrees of freedoms as ``Higgs...
Vacuum structure and dynamical symmetry breaking in gauge-Higgs unification models (2004)
Haba, Naoyuki, Yamashita, Toshifumi
This paper has been withdrawn by the authors, because the authors have second thought that the new ideas in this paper are better to be contained in another paper.
A general formula of the effective potential in 5D SU(N) gauge theory on orbifold (2004)
Haba, Naoyuki, Yamashita, Toshifumi
We show a general formula of the one loop effective potential of the 5D SU(N) gauge theory compactified on an orbifold, $S^1/Z_2$. The formula shows the case when there are fundamental,...
Sliding Singlet Mechanism Revisited (2003)
Maekawa, Nobuhiro, Yamashita, Toshifumi
We show that the unification of the doublet Higgs in the standard model (SM) and the Higgs to break the grand unified theory (GUT) group stabilizes the sliding singlet mechanism which can solve the...
Maekawa, Nobuhiro, Yamashita, Toshifumi
We show that as in the flipped SU(5) models, doublet-triplet splitting is realized by the missing partner mechanism in the flipped SO(10) models. The gauge group $SO(10)_F\times U(1)_{V'_F}$ includes...
Simple $E_6$ Unification with Anomalous $U(1)_A$ Symmetry (2003)
Maekawa, Nobuhiro, Yamashita, Toshifumi
We propose simpler Higgs sectors in $E_6$ grand unified theory with anomalous $U(1)_A$ gauge symmetry than the previous model in Ref.1). As in the previous model, the doublet-triplet splitting can be...
Gauge Coupling Unification in GUT with Anomalous U(1) Symmetry (2002)
Maekawa, Nobuhiro, Yamashita, Toshifumi
We show that in the framework of grand unified theory (GUT) with anomalous $U(1)_A$ gauge symmetry, the success of the gauge coupling unification in the minimal SU(5) GUT is naturally explained, even...
Two-Loop Analysis of Gauge Coupling Unification with Anomalous U(1) Symmetry and Proton Decay (2002)
Maekawa, Nobuhiro, Yamashita, Toshifumi
Recently, a new mechanism, which explains why the three gauge coupling constants meet at a certain scale in the minimal supersymmetric standard model, has been proposed in a scenario of grand unified...
E_6 Unification, Doublet-Triplet Splitting and Anomalous U(1)_A Symmetry (2002)
Maekawa, Nobuhiro, Yamashita, Toshifumi
We propose a natural Higgs sector in E_6 grand unified theory (GUT) with anomalous U(1)_A gauge symmetry. In the scenario, the doublet-triplet splitting can be realized while the proton decay via...