掲載種別：研究論文（学術雑誌）  

Grand gauge-Higgs unification of five dimensional SU(6) gauge theory on an
orbifold $S^1/Z_2$ with localized gauge kinetic terms is discussed. The
Standard model (SM) fermions on the boundaries and some massive bulk fermions
coupling to the SM fermions on the boundary are introduced. Taking the
power-law running contributions from the bulk fields into account, perturbative
gauge coupling unification is shown to be realized at around $10^{14}$ GeV,
which is a few order smaller than the unification scale of four dimensional
grand unified theories.

その他URL： http://arxiv.org/pdf/2207.10253v1

掲載種別：研究論文（学術雑誌）  

Cosmological Collider Physics provides information on high-energy elementary
particles by observing the spacetime fluctuations generated by inflation
through the cosmic microwave background radiation. In other words, it is a
method to investigate physics on energy scales that cannot be reached by
terrestrial accelerators by means of precise observations of the universe. In
this paper, we focus on the case where the GUT scale is close to the energy
scale of inflation, and calculate the non-Gaussianity due to scalar
fluctuations produced by the Higgs boson in GUT. The results are found to be
consistent with the current observed restrictions on non-Gaussianity without a
drastic fine tuning of parameters, which suggests the existence of Higgs boson
in GUT.

その他URL： http://arxiv.org/pdf/2206.06651v1

掲載種別：研究論文（学術雑誌）  

We discuss the gauge symmetry breaking of six dimensional theories in flux
compactification with a magnetic flux background and a constant vacuum
expectation value (VEV) for the scalar fields, which are zero modes of extra
spatial components of the gauge field. Although the effective potential for the
scalar fields are known not to be generated classically and radiatively in a
magnetic flux background only, the one-loop effective potential is shown to be
generated by the effects of the non-zero constant VEV. As illustrations, we
calculate the one-loop effective potential in SU(2) and SU(3) Yang-Mills
theories. In both cases, we find that the potential minimum is located at
non-zero VEV and the gauge symmetry breaking takes place.

その他URL： http://arxiv.org/pdf/2205.09320v2

掲載種別：研究論文（学術雑誌）  

Grand gauge-Higgs unification of five dimensional SU(6) gauge theory on an
orbifold $S^1 / Z_2$ with localized gauge kinetic terms is discussed. The
Standard model (SM) fermions on the boundaries and some massive bulk fermions
coupling to the SM fermions are introduced. The number of the bulk fermions is
reduced to realize perturbative gauge coupling unification, which could not be
done in the previous model. Although this reduction will lead to the additional
generation mixings in the bulk which makes our analysis more complicated and
nontrivial, the generation mixing of the SM fermions is reproduced in addition
to the SM fermion mass hierarchy by mild tuning the bulk masses and parameters
of the localized gauge kinetic terms.

その他URL： http://arxiv.org/pdf/2205.05824v1

掲載種別：研究論文（学術雑誌）  

In this paper, we discuss the vacuum structure of the gauge-Higgs unification
theory, which is one of the attractive candidates of physics beyond the
standard model. This scenario has a remarkable feature, namely it has
infinitely degenerate vacua due to the characteristic periodic potential of the
Higgs filed, to be identified with the extra space component of the higher
dimensional gauge field. We address a question, whether to form the
superposition of such degenerate vacua, like the $\theta$-vacuum in QCD, is
necessary or not, in order to realize the true vacuum state of the theory. We
derive gauge field configuration which describes the transition between
neighboring vacua, like the instanton (or anti-instanton) solution in QCD, and
the corresponding Euclidean action in two models. In a simplified 2-dimensional
U(1) model, the derived configuration to describe the transition is shown to
have finite Euclidean action, and accordingly the "$\theta$-vacuum" and the
resultant "$\theta$-term" are formulated. In a realistic 5D U(1) model,
however, the gauge field configuration to describe the transition is shown to
have infinite Euclidean action and therefore the tunneling probability between
the degenerate vacua vanishes. Thus the superposition of the degenerate vacua
is not necessary.

その他URL： http://arxiv.org/pdf/2205.00161v1

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/JHEP09(2021)124

掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/ptep/ptac070

その他URL： http://arxiv.org/pdf/2108.07367v1

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/JHEP06(2021)159

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/JHEP09(2021)124

その他URL： http://arxiv.org/pdf/2105.11782v2

掲載種別：研究論文（学術雑誌）  

DOI： 10.1088/1361-6471/abddce

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/JHEP06(2021)159

その他URL： http://arxiv.org/pdf/2104.01779v2

掲載種別：研究論文（学術雑誌）  

Heavy fields of Hubble scale order present during inflation contribute to the
non-Gaussian signature for the three-point function of the inflaton. Taking
into account that Hubble scale is around the scale of grand unified theory
(GUT), this opens a possibility that the GUT scale signatures, which are very
hard to be discovered at collider, might be detectable by using information
from the precise observations of cosmic microwave background. We discuss a
detactability of the $X, Y$ gauge boson present in any GUT in a framework of
cosmological collider physics. Calculating one-loop contributions of $X, Y$
gauge bosons to the inflaton three-point functions, we find a remarkable result
that one-loop diagram with interactions originated from the mass terms of $X,
Y$ gauge bosons provides an enhancement factor expressed by the ratio between
the $X, Y$ gauge boson mass and Hubble scale as $(m_X/H)^4$. In an estimation
of the non-Gaussianity, this factor is crucial and its impact on the
detactability of $X, Y$ gauge bosons is discussed.

その他URL： http://arxiv.org/pdf/2101.10634v1

掲載種別：研究論文（学術雑誌）  

DOI： 10.1088/1361-6471/abddce

その他URL： http://arxiv.org/pdf/2012.03494v1

掲載種別：研究論文（学術雑誌）  

DOI： 10.1140/epjc/s10052-020-08485-8

掲載種別：研究論文（学術雑誌）  

DOI： 10.1103/PhysRevD.101.036013

掲載種別：研究論文（学術雑誌）  

掲載種別：研究論文（学術雑誌）  

DOI： 10.1103/PhysRevD.101.036013

その他URL： http://arxiv.org/pdf/1911.05963v1

掲載種別：研究論文（学術雑誌）  

DOI： 10.1140/epjc/s10052-020-08485-8

その他URL： http://arxiv.org/pdf/1911.03465v3

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/JHEP08(2019)054

掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/ptep/ptz083

掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/JHEP08(2019)054

その他URL： http://arxiv.org/pdf/1904.06028v1

掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/ptep/ptz083

その他URL： http://arxiv.org/pdf/1903.08359v2

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.74.1.0_10

CiNii Article

掲載種別：研究論文（学術雑誌）  

A new vector dark matter (DM) scenario in the context of the gauge-Higgs
unification (GHU) is proposed. The DM particle is identified with an
electric-charge neutral component in an $SU(2)_L$ doublet vector field with the
same quantum number as the Standard Model Higgs doublet. Since such an
$SU(2)_L$ doublet vector field is incorporated in any models of the GHU
scenario, it is always a primary and model-independent candidate for the DM in
the scenario. The observed relic density is reproduced through a DM pair
annihilations into the weak gauge bosons with a TeV-scale DM mass, which is
nothing but the compactification scale of extra-dimensions. Due to the
higher-dimensional gauge structure of the GHU scenario, a pair of the DM
particles has no direct coupling with a single $Z$-boson/Higgs boson, so that
the DM particle evades the severe constraint from the current direct DM search
experiments.

DOI： 10.1103/PhysRevD.98.075021

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.73.2.0_18

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.73.2.0_18

CiNii Article

掲載種別：研究論文（学術雑誌）   共著区分：単著  

DOI： 10.1142/S0217751X17470200

掲載種別：研究論文（学術雑誌）  

We propose a Minimal Dark Matter (MDM) scenario in the context of a simple
gauge-Higgs Unification (GHU) model based on the gauge group SU(3) x U(1)' in
5-dimensional Minkowski space with a compactification of the 5th dimension on
S^1/Z_2 orbifold. A pair of vector-like SU(3) multiplet fermions in a
higher-dimensional representation is introduced in the bulk, and the DM
particle is identified with the lightest mass eigenstate among the components
in the multiplets. In the original model description, the DM particle
communicates with the Standard Model (SM) particles only through the bulk gauge
interaction, and hence our model is the GHU version of the MDM scenario. There
are two typical realizations of the DM particle in 4-dimensional effective
theory: (i) the DM particle is mostly composed of the SM SU(2)_L multiplets, or
(ii) the DM is mostly composed of the SM SU(2)_L singlets. Since the case (i)
is very similar to the original MDM scenario, we focus on the case (ii), which
is a realization of the Higgs-portal DM scenario in the context of the GHU
model. We identify an allowed parameter region to be consistent with the
current experimental constraints, which will be fully covered by the direct
dark matter detection experiments in the near future. In the presence of the
bulk multiplet fermions in higher-dimensional $SU(3)$ representations, we
reproduce the 125 GeV Higgs boson mass through the renormalization group
evolution of Higgs quartic coupling with the compactification scale of 10-100
TeV.

DOI： 10.1103/PhysRevD.96.115023

掲載種別：研究論文（学術雑誌）  

We propose a Majorana fermion dark matter in the context of a simple
gauge-Higgs Unification (GHU) scenario based on the gauge group $SU(3)$ x
$U(1)'$ in 5-dimensional Minkowski space with a compactification of the 5th
dimension on $S^1/Z_2$ orbifold. The dark matter particle is identified with
the lightest mode in $SU(3)$ triplet fermions additionally introduced in the
5-dimensional bulk. We find an allowed parameter region for the dark matter
mass around a half of the Standard Model Higgs boson mass, which is consistent
with the observed dark matter density and the constraint from the LUX 2016
result for the direct dark matter search. The entire allowed region will be
covered by, for example, the LUX-ZEPLIN dark matter experiment in the near
future. We also show that in the presence of the bulk $SU(3)$ triplet fermions
the 125 GeV Higgs boson mass is reproduced through the renormalization group
evolution of Higgs quartic coupling with the compactification scale of around
$10^8$ GeV.

DOI： 10.1007/JHEP07(2017)048

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.72.2.0_24

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.72.2.0_24

CiNii Article

掲載種別：研究論文（学術雑誌）  

We examine trilinear gauge boson couplings (TGCs) in the context of the
$SU(3)_W\otimes U(1)'$ gauge-Higgs unification scenario. The TGCs play
important roles in the probes of the physics beyond the standard model, since
they are highly restricted by the experiments. We discuss mass spectrum of the
neutral gauge boson with brane-localized mass terms carefully and find that the
TGCs and $\rho$ parameter may deviate from standard model predictions. Finally
we put a constraint from these observables and discuss the possible parameter
space.

DOI： 10.1093/ptep/ptw088

掲載種別：研究論文（学術雑誌）   共著区分：単著  

A recently proposed new mechanism of D-term triggered dynamical supersymmetry
breaking is reviewed. Supersymmetry is dynamically broken by nonvanishing
D-term vacuum expectation value, which is realized as a nontrivial solution of
the gap equation in the self-consistent approximation as in the case of
Nambu-Jona-Lasinio model and BCS superconductivity.

DOI： 10.1093/ptep/ptw018

掲載種別：研究論文（学術雑誌）  

DOI： 10.1140/epjp/i2015-15168-3

掲載種別：研究論文（学術雑誌）  

We address a question whether the recently observed Higgs mass $M_{H} = 126$
GeV, of the order of the weak scale $M_{W}$, is calculable as a finite value in
the scnenario of gauge-Higgs unification. In the scenario formulated on a flat
5-dimensional space-time, the Higgs mass is calculable, being protected under
the quantum correction by gauge invariance, though the predicted Higgs mass is
generally too small compared with $M_{W}$. In the 6-dimensional SU(3) model,
however, a suitable orbifolding is known to lead to a mass of the order of
$M_{W}$: $M_{H} = 2M_{W}$ at the tree level, which has some similarity to the
corresponding prediction by the MSSM, $M_{H}$ leq (cos beta) $M_{Z}$. We
demonstrate first by a general argument and secondly by explicit calculations
that, even though the quantum correction to the quartic self-coupling of the
Higgs field is UV-divergent, its deviation from that of $g^{2}$ is calculable,
and therefore two observables, $M_{H}^{2}$ and Delta equiv
$(M_{H}/2M_{W})^{2}-1$, are both calculable in the gauge-Higgs unification
scenario. The implication of the precise value 126 GeV to the compactification
scale and the bulk mass of the matter field in our model is also discussed.

DOI： 10.1093/ptep/ptv030

掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/sym7010193

掲載種別：研究論文（学術雑誌）  

In our previous paper, we have investigated effects of a simple gauge-Higgs
unification model on the diphoton signal events from the Higgs boson production
at the Large Hadron Collider. We have found that in this model the effective
Higgs-to-diphoton coupling can be enhanced by 1-loop corrections with
Kaluza-Klein (KK) modes of bulk fields. This result can be an explanation for
the observed excess of the signal strength in the Higgs to diphoton decay
channel. In this paper, we investigate KK-mode effects on another Higgs boson
decay mode, H to Z gamma. One naturally expects that the KK modes also
contribute to the effective H-Z-gamma coupling and can cause some deviation for
the H to Z gamma decay mode from the Standard Model prediction. Revealing a
correlation between the KK-mode effects on the Higgs-to-diphoton and H-Z-gamma
couplings is an interesting topic in terms of a possibility to discriminate a
variety of models for physics beyond the Standard Model. We show a very
striking result for the gauge-Higgs unification model, namely, the absence of
KK-mode contributions to the H-Z-gamma coupling at the 1-loop level. This is a
very specific and general prediction of the gauge-Higgs unification scenario.

DOI： 10.1103/PhysRevD.88.037701

掲載種別：研究論文（学術雑誌）  

We present the mechanism of the dynamical supersymmetry breaking at the
metastable vacuum recently uncovered in the N=1 U(N) supersymmetric gauge
theory that contains adjoint superfields and that is specified by Kahler and
non-canonical gauge kinetic functions and a superpotential whose tree vacua
preserve N=1 supersymmetry. The overall U(1) serves as the hidden sector and no
messenger superfield is required. The dynamical supersymmetry breaking is
triggered by the non-vanishing D term coupled to the observable sector, and is
realized by the self-consistent Hartree-Fock approximation of the NJL type
while it eventually brings us the non-vanishing F term as well. It is shown
that theoretical analysis is resolved as a variational problem of the effective
potential for three kinds of background fields, namely, the complex scalar, and
the two order parameters D and F of supersymmetry, the last one being treated
perturbatively. We determine the stationary point and numerically check the
consistency of such treatment as well as the local stability of the scalar
potential. The coupling to the N = 1 supergravity is given and the gravitino
mass formula is derived.

DOI： 10.1103/PhysRevD.88.025012

掲載種別：研究論文（学術雑誌）  

DOI： 10.11316/jpsgaiyo.68.2.1.0_4_4

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.24532/soken.119.3_C33

CiNii Article

掲載種別：研究論文（学術雑誌）  

We discuss flavor mixing and resultant flavor changing neutral current rocesses in the SU(3) circle times SU(3)(color) gauge-Higgs unification scenario. To achieve flavor violation is a challenging issue in the scenario, since the Yukawa couplings are originally higher dimensional gauge interactions. We argue that the presence of Z(2)-odd bulk masses of fermions plays a crucial role as the new source of flavor violation. Although introducing brane-localized mass terms in addition to the bulk masses is necessary to realize flavor mixing, if the bulk masses were universal among generations, the flavor mixing and flavor changing neutral current processes are known to disappear. We also discuss whether natural flavor conservation is realized in the scenario. It is shown that the new source of flavor violation leads to flavor changing neutral current processes at the tree level due to the exchange of non-zero Kaluza-Klein gauge bosons. As a typical example we calculate the rate of K-0 - (K) over bar (0) mixing due to the non-zero Kaluza-Klein gluon exchange at the tree level. The obtained result for the mass difference of neutral kaon is suppressed by the inverse powers of the compactification scale. By comparing our prediction with the data we obtain the lower bound of the compactification scale as a function of one unfixed parameter of the theory, which is of O(10) TeV, except for some extreme cases. We argue that the reason to get such rather mild lower bound is the presence of "GIM-like" mechanism, which is a genuine feature of GHU scenario.

DOI： 10.1007/JHEP11(2010)150

掲載種別：研究論文（学術雑誌）  

We discuss flavor mixing and resultant flavor changing neutral current rocesses in the SU(3) circle times SU(3)(color) gauge-Higgs unification scenario. To achieve flavor violation is a challenging issue in the scenario, since the Yukawa couplings are originally higher dimensional gauge interactions. We argue that the presence of Z(2)-odd bulk masses of fermions plays a crucial role as the new source of flavor violation. Although introducing brane-localized mass terms in addition to the bulk masses is necessary to realize flavor mixing, if the bulk masses were universal among generations, the flavor mixing and flavor changing neutral current processes are known to disappear. We also discuss whether natural flavor conservation is realized in the scenario. It is shown that the new source of flavor violation leads to flavor changing neutral current processes at the tree level due to the exchange of non-zero Kaluza-Klein gauge bosons. As a typical example we calculate the rate of K-0 - (K) over bar (0) mixing due to the non-zero Kaluza-Klein gluon exchange at the tree level. The obtained result for the mass difference of neutral kaon is suppressed by the inverse powers of the compactification scale. By comparing our prediction with the data we obtain the lower bound of the compactification scale as a function of one unfixed parameter of the theory, which is of O(10) TeV, except for some extreme cases. We argue that the reason to get such rather mild lower bound is the presence of "GIM-like" mechanism, which is a genuine feature of GHU scenario.

DOI： 10.1007/JHEP11(2010)150

その他URL： http://arxiv.org/pdf/1005.2455v4

掲載種別：研究論文（学術雑誌）  

We address the challenging issue of how CP violation is realized in higher dimensional gauge theories without higher dimensional elementary scalar fields. In such theories interactions are basically governed by a gauge principle and therefore to get CP violating phases is a nontrivial task. It is demonstrated that CP violation is achieved as the result of compactification of extra dimensions, which is incompatible with the 4-dimensional CP transformation. As a simple example we adopt a 6-dimensional U(1) model compactified on a 2-dimensional orbifold T2/Z4. We argue that the 4-dimensional CP transformation is related to the complex structure of the extra space and show how the Z4 orbifolding leads to CP violation. We confirm by explicit calculation of the interaction vertices that CP violating phases remain even after the rephasing of relevant fields. For completeness, we derive a rephasing invariant CP violating quantity, following a similar argument in the Kobayashi-Maskawa model which led to the Jarlskog parameter. As an example of a CP violating observable we briefly comment on the electric dipole moment of the electron. © 2010 The American Physical Society.

DOI： 10.1103/PhysRevD.81.076006

掲載種別：研究論文（学術雑誌）  

We address the challenging issue of how CP violation is realized in higher dimensional gauge theories without higher dimensional elementary scalar fields. In such theories interactions are basically governed by a gauge principle and therefore to get CP violating phases is a nontrivial task. It is demonstrated that CP violation is achieved as the result of compactification of extra dimensions, which is incompatible with the 4-dimensional CP transformation. As a simple example we adopt a 6-dimensional U(1) model compactified on a 2-dimensional orbifold T2/Z4. We argue that the 4-dimensional CP transformation is related to the complex structure of the extra space and show how the Z4 orbifolding leads to CP violation. We confirm by explicit calculation of the interaction vertices that CP violating phases remain even after the rephasing of relevant fields. For completeness, we derive a rephasing invariant CP violating quantity, following a similar argument in the Kobayashi-Maskawa model which led to the Jarlskog parameter. As an example of a CP violating observable we briefly comment on the electric dipole moment of the electron. © 2010 The American Physical Society.

DOI： 10.1103/PhysRevD.81.076006

掲載種別：研究論文（学術雑誌）  

DOI： 10.24532/soken.117.6_F58

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.24532/soken.117.6_F84

CiNii Article

掲載種別：研究論文（学術雑誌）  

We study the neutron electric dipole moment (EDM) in a five-dimensional SU(3) gauge-Higgs unification compactified on M4×S1/Z2 space-time including a massive fermion. We point out that to realize the CP violation is a nontrivial task in the gauge-Higgs unification scenario and argue how the CP symmetry is broken spontaneously by the vacuum expectation value of the Higgs, the extra space component of the gauge field. We emphasize the importance of the interplay between the vacuum expectation value of the Higgs and the Z2-odd bulk mass term to get physically the CP violation. We then calculate the one-loop contributions to the neutron EDM as the typical example of the CP violating observable and find that the EDM appears already at the one-loop level, without invoking the three-generation scheme. We then derive a lower bound for the compactification scale, which is around 2.6 TeV, by comparing the contribution due to the nonzero Kaluza-Klein modes with the experimental data. © 2009 The American Physical Society.

DOI： 10.1103/PhysRevD.80.055025

掲載種別：研究論文（学術雑誌）  

We study the neutron electric dipole moment (EDM) in a five-dimensional SU(3) gauge-Higgs unification compactified on M4×S1/Z2 space-time including a massive fermion. We point out that to realize the CP violation is a nontrivial task in the gauge-Higgs unification scenario and argue how the CP symmetry is broken spontaneously by the vacuum expectation value of the Higgs, the extra space component of the gauge field. We emphasize the importance of the interplay between the vacuum expectation value of the Higgs and the Z2-odd bulk mass term to get physically the CP violation. We then calculate the one-loop contributions to the neutron EDM as the typical example of the CP violating observable and find that the EDM appears already at the one-loop level, without invoking the three-generation scheme. We then derive a lower bound for the compactification scale, which is around 2.6 TeV, by comparing the contribution due to the nonzero Kaluza-Klein modes with the experimental data. © 2009 The American Physical Society.

DOI： 10.1103/PhysRevD.80.055025

掲載種別：研究論文（学術雑誌）  

We discuss the anomalous magnetic moment of fermion in a realistic SU(3) model of gauge-Higgs unification compactified on an orbifold S1/Z2 including Z2-odd bulk mass for fermions. An operator analysis implies that the anomalous magnetic moment should be finite and predictable, even though higher dimensional gauge theories are nonrenormalizable. Our main purpose is to clarify the cancellation mechanism of the UV divergences appearing in various types of Feynman diagrams. The cancellation of divergence turns out to take place between the contributions of the partners in the Higgs-like mechanism present in the nonzero Kaluza-Klein modes to form massive gauge bosons. It is also argued that the cancellation may be attributed to the quantum mechanical supersymmetry hidden in the scenario of gauge-Higgs unification. © 2009 The American Physical Society.

DOI： 10.1103/PhysRevD.79.075018

掲載種別：研究論文（学術雑誌）  

We discuss the anomalous magnetic moment of fermion in a realistic SU(3) model of gauge-Higgs unification compactified on an orbifold S1/Z2 including Z2-odd bulk mass for fermions. An operator analysis implies that the anomalous magnetic moment should be finite and predictable, even though higher dimensional gauge theories are nonrenormalizable. Our main purpose is to clarify the cancellation mechanism of the UV divergences appearing in various types of Feynman diagrams. The cancellation of divergence turns out to take place between the contributions of the partners in the Higgs-like mechanism present in the nonzero Kaluza-Klein modes to form massive gauge bosons. It is also argued that the cancellation may be attributed to the quantum mechanical supersymmetry hidden in the scenario of gauge-Higgs unification. © 2009 The American Physical Society.

DOI： 10.1103/PhysRevD.79.075018

その他URL： http://arxiv.org/pdf/0901.2229v2

掲載種別：研究論文（学術雑誌）  

DOI： 10.24532/soken.116.3_C20

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.24532/soken.114.4_D101

CiNii Article

掲載種別：研究論文（学術雑誌）  

DOI： 10.24532/soken.110.4_D64

CiNii Article

著書種別：学術書  

著書種別：学術書  

著書種別：学術書  

著書種別：学術書  

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Very recently, the CMS collaboration has reported a search for the production<br />
for a Standard Model (SM) Higgs boson in association with a top quark pair ($t<br />
bar{t} H$) at the LHC Run-2 and a best fit $t bar{t} H$ yield of $1.5 pm 0.5$<br />
times the SM prediction with an observed significance of $3.3 sigma$. We study<br />
a possibility of whether or not this observed deviation can be explained by<br />
anomalous Higgs Yukawa couplings with the top and the bottom quarks, along with<br />
the LHC Run-1 data for the Higgs boson properties. We find that anomalous top<br />
and bottom Yukawa couplings with about $0-20$% and $10-40$% reductions from<br />
their SM values, respectively, can simultaneously fit the recent CMS result and<br />
the LHC Run-1 data.

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study gauge coupling unification in supersymmetric (SUSY) E-6 models where an additional U(1)' gauge symmetry is broken near the TeV scale and a number of exotic matter fields from the 27 representations have O(TeV) mass. Solving the two-loop renormalization group equations (RGE) of gauge couplings and a kinetic mixing coupling between the U(1)' and U(1)(Y) gauge fields, we find that the gauge couplings fall into the non-perturbative regime below the grand unified theories (GUT) scale. We examine threshold corrections on the running of gauge couplings from both light and heavy (similar to GUT scale) particles and show constraints on the size of corrections to achieve the perturbative unification of gauge couplings.

DOI： 10.1142/S0217732316501303

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We examine trilinear gauge boson couplings (TGCs) in the context of the SU(3)(W) circle times U(1)' gauge-Higgs unification scenario. The TGCs play important roles in probes of the physics beyond the standard model, since they are highly restricted by the experiments. We discuss the mass spectrum of the neutral gauge boson with brane-localized mass terms carefully and find that the TGCs and rho parameter may deviate from standard model predictions. Finally, we put a constraint on these observables and discuss the possible parameter space.

DOI： 10.1093/ptep/ptw088

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In the gauge-Higgs unification with multiple extra spaces, the Higgs self-coupling is on the order of g(2) and the Higgs boson is predicted to be light, being consistent with the LHC results. When the gauge group is simple, the weak mixing angle is also predictable. We address a question on whether there exists a model of gauge-Higgs unification in six-dimensional space-time, which successfully predicts the mass ratios of the Higgs boson and weak gauge bosons. First, using a useful formula, we give a general argument on the condition for obtaining a realistic prediction of the weak mixing angle sin(2)theta(W) = 1/4, and find that triplet and sextet representations of the minimal SU(3) gauge group lead to the realistic prediction. Concerning the Higgs mass, we notice that, in the models with one Higgs doublet, the predicted Higgs mass is always the same: M-H = 2M(W). However, by extending our discussion to the models with two Higgs doublets, the situation changes: we obtain an interesting prediction M-H &lt;= 2M(W) at the leading order of the perturbation. Thus, it is possible to recover the observed Higgs mass, 125 GeV, for a suitable choice of the parameter. The situation is in clear contrast to the case of the minimal supersymmetric standard model, where M-H &lt;= M-Z at the classical level and the predicted Higgs mass cannot recover the observed value.

DOI： 10.7566/JPSJ.85.074101

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

A recently proposed new mechanism of D-term-triggered dynamical supersymmetry breaking is reviewed. Supersymmetry is dynamically broken by a nonvanishing D-term vacuum expectation value, which is realized as a nontrivial solution of the gap equation in the self-consistent approximation, as in the case of the Nambu-Jona-Lasinio model and BCS superconductivity.

DOI： 10.1093/ptep/ptw018

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In some extensions of the Standard Model, Yukawa couplings of the physical<br />
Higgs boson can be deviated from those in the Standard Model. We study a<br />
possibility whether or not such anomalous Yukawa couplings are consistent with<br />
the LHC Run 1 data. It is found that sizable deviations of top and bottom (and<br />
tau) Yukawa couplings from the Standard Model predictions can nicely fit the<br />
data. New physics beyond the Standard Model can be revealed through more<br />
precise measurements of such anomalous Yukawa couplings at the LHC Run 2 in the<br />
near future. We also discuss a simple setup which can leads to anomalous Yukawa<br />
couplings.

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study the deviation of the Yukawa coupling in the gauge-Higgs unification scenario from the Standard Model one. Taking into account the brane mass terms necessary for generating the flavor mixing and removing the exotic massless fermions, we derive an analytic formula determining the KK mass spectrum and Yukawa coupling. Applying the obtained results to the tau and bottom Yukawa couplings, we numerically calculate the ratio of the Yukawa couplings in the gauge-Higgs unification and in the Standard Model.

DOI： 10.1140/epjp/i2015-15168-3

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study the deviation of the Yukawa coupling in the gauge-Higgs unification scenario from the Standard Model one. Taking into account the brane mass terms necessary for generating the flavor mixing and removing the exotic massless fermions, we derive an analytic formula determining the KK mass spectrum and Yukawa coupling. Applying the obtained results to the tau and bottom Yukawa couplings, we numerically calculate the ratio of the Yukawa couplings in the gauge-Higgs unification and in the Standard Model.

DOI： 10.1140/epjp/i2015-15168-3

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We address the question of whether the recently observed Higgs mass M-H = 126 GeV, of the order of the weak scale MW, is calculable as a finite value in the scenario of gauge-Higgs unification. In the scenario formulated on a flat five-dimensional space-time, the Higgs mass is calculable, being protected under the quantum correction by gauge invariance, though the predicted Higgs mass is generally too small compared with M-W. In the six-dimensional SU(3) model, however, a suitable orbifolding is known to lead to a mass of the order of M-W: M-H = 2M(W) at the tree level, which has some similarity to the corresponding prediction by the minimal supersymmetric standard model, M-H &lt;= (cos beta) M-Z.
We demonstrate first by a general argument and secondly by explicit calculations that, even though the quantum correction to the quartic self-coupling of the Higgs field is UV-divergent, its deviation from that of g(2) is calculable, and therefore two observables, M-H(2) and Delta equivalent to (M-H/2M(W))(2) - 1, are both calculable in the gauge-Higgs unification scenario. The implication of the precise value 126 GeV to the compactification scale and the bulk mass of the matter field in our model is also discussed.

DOI： 10.1093/ptep/ptv030

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We present an extension of the mass sum rule that applies to renormalizable rigid supersymmetric field theories to the case of the N = 1 supersymmetric effective action (the gauged non-linear sigma model) consisting of adjoint scalar superfields and vector superfields possessing a Kahler potential, a set of gauge coupling functions (second prepotential derivatives) and a superpotential, which respectively set their energy scales. The mass sum rule derived is valid for any vacua, including the (metastable) one of broken supersymmetry with the condensates of D-term and/or F-term. We manage to extend these analyses to the cases where superfields in (anti-)fundamental representation are present. The supertrace is shown to vanish in those cases where underlying geometry is special Kahler and theory under concern is anomaly free. Simple phenomenological application is given, providing an upper bound for gaugino masses. We discuss that the effects of the D and/or F condensates can be represented as a set of soft breaking terms with their strengths predicted by the scales. (C) 2015 The Authors. Published by Elsevier B.V.

DOI： 10.1016/j.nuclphysb.2015.02.017

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We discuss a new mechanism of D-term dynamical supersymmetry breaking in the<br />
context of Dirac gaugino scenario. The existence of a nontrivial solution of<br />
the gap equation for D-term is shown. It is also shown that an observed 126 GeV<br />
Higgs mass is realized by tree level D-term effects in a broad range of<br />
parameters.

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We have studied the Kaluza-Klein (KK) mode contributions to the diphoton<br />
decay of Higgs boson through the gluon fusion at LHC in a five dimensional<br />
$SU(3) times U(1)&#039;$ gauge-Higgs unification (GHU) model. The minimal matter<br />
content case is found that the diphoton decay is necessarily destructive<br />
comparing to the Standard Model (SM) prediction, which is unfortunately not<br />
supported by the current experimental data. Two extensions are considered to<br />
not only enhance the diphoton decay but also realize an observed Higgs mass.<br />
The $Z gamma$ decay of Higgs boson is also studied and the striking result is<br />
found that there is no KK mode contributions to the decay at 1-loop level. This<br />
fact might be very useful to discriminate the GHU from other physics beyond the<br />
SM.

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study the deviation of Higgs production through the gluon fusion process<br />
and the decay of Higgs boson to the bottom quark and the tau lepton in<br />
gauge-Higgs unification from the Standard Model prediction. We find that the<br />
signal strength of $gg \to H \to b\bar{b}, \tau\bar{\tau}$ is necessarily<br />
suppressed comparing to the SM predictions due to the dominant suppression of<br />
the Higgs production via gluon fusion.

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Continuing with our previous work on D-term triggered dynamical supersymmetry breaking, we consider a system in which our generic N = 1 action is minimally extended to include the pair of Higgs doublet superfields charged under the overall U(1) together with μ and Bμ terms. The gauge group is taken to be SU(3)C × SU(2)L × U(1)Y × U(1). We point out, among other things, that the Higgs mass less than the Z-boson mass at tree level can be pushed up to be around 126 GeV by D-term contributions of the overall U(1). This is readily realized by taking a U(1) gauge coupling to be O(1).

DOI： 10.3390/sym7010193

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We investigate a radiative correction to the masses of Kaluza-Klein (KK) modes in a universal extra-dimensional model defined on a six-dimensional spacetime with extra space as a two-sphere orbifold S-2/Z(2). We first define the Feynman rules which are necessary for the calculation. We then calculate the one-loop diagrams which contribute to the radiative corrections to the KK masses, and obtain one-loop corrections to masses for fermions, gauge bosons, and scalar bosons. We estimate the one-loop corrections to KK masses for the first KK modes of standard model particles as a function of momentum cut-off scale, and we determine the lightest KK particle which would be a promising candidate for dark matter.

DOI： 10.1093/ptep/ptu113

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

The two dominant processes of lepton flavor violation, mu to 3e and mu to e<br />
conversion in atomic nuclei caused by neutral KK gauge boson exchanges at tree<br />
level, are studied in the context of five dimensional gauge-Higgs unification<br />
scenario. The key point of the flavor violation is a fact that the bulk masses<br />
and the brane ones cannot be simultaneously diagonalized. We estimate the<br />
branching ratio of each processes and obtain the lower bound of<br />
compactification scale around weak scale from the current experimental data. We<br />
discuss the reasons why the final result is not so severe although the large<br />
mixing in the lepton sector seems to give large lepton flavor violation<br />
processes.

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In the context of a simple gauge-Higgs unification scenario based on the<br />
gauge group SU(3) times U(1)&#039; in a 5-dimensional flat spacetime, we investigate<br />
a possibility to realize the Higgs boson mass of 125 GeV with a<br />
compactification scale at the TeV. With the introduction of colored bulk<br />
fermions in a certain representation under the gauge group with a half-periodic<br />
boundary condition, we analyze the one-loop RGE of the Higgs quartic coupling<br />
with the gauge-Higgs condition and successfully obtain 125 GeV Higgs boson mass<br />
by adjusting a bulk mass for the fermions with a fixed compactification scale.<br />
The Kaluza-Klein modes of the colored fermions contribute to the<br />
Higgs-to-digluon effective coupling through the one-loop corrections. Since the<br />
contribution is destructive to the Standard Model one and reduces the Higgs<br />
boson production cross section, the recent LHC result gives a lower bound on<br />
the mass of the lightest Kaluza-Klein mode fermion. We find the mass of the<br />
lightest Kaluza-Klein mode fermion in the range of 2-3 TeV for 10%-5%<br />
reductions of the Higgs boson production cross section through the gluon fusion<br />
channel. Such Kaluza-Klein mode fermions can be discovered at the LHC run II<br />
with sqrt{s}=13-14 TeV, and LHC phenomenology for the Kaluza-Klein fermions is<br />
briefly discussed.

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In our previous paper [N. Maru and N. Okada, Phys. Rev. D 87, 095019 (2013)], we have investigated effects of a simple gauge-Higgs unification model on the diphoton signal events from the Higgs boson production at the Large Hadron Collider. We have found that in this model the effective Higgs-to-diphoton coupling can be enhanced by 1-loop corrections with Kaluza-Klein (KK) modes of bulk fields. This result can be an explanation for the observed excess of the signal strength in the Higgs-to-diphoton decay channel. In this paper, we investigate KK-mode effects on another Higgs boson decay mode, H -&gt; Z gamma. One naturally expects that the KK modes also contribute to the effective H-Z-gamma coupling and can cause some deviation for the H -&gt; Z gamma decay mode from the Standard Model prediction. Revealing a correlation between the KK-mode effects on the Higgs-to-diphoton and H-Z-gamma couplings is an interesting topic in terms of a possibility to discriminate a variety of models for physics beyond the Standard Model. We show a very striking result for the gauge-Higgs unification model, namely, the absence of KK-mode contributions to the H-Z-gamma coupling at the 1-loop level. This is a very specific and general prediction of the gauge-Higgs unification scenario.

DOI： 10.1103/PhysRevD.88.037701

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We present the mechanism of the dynamical supersymmetry breaking at the metastable vacuum recently uncovered in the N=1 U(N) supersymmetric gauge theory that contains adjoint superfields and that is specified by Kähler and noncanonical gauge kinetic functions and a superpotential whose tree vacua preserve N=1 supersymmetry. The overall U(1) serves as the hidden sector, and no messenger superfield is required. The dynamical supersymmetry breaking is triggered by the nonvanishing D term coupled to the observable sector and is realized by the self-consistent Hartree-Fock approximation of the Nambu-Jona-Lasinio type while it eventually brings us the nonvanishing F term as well. It is shown that theoretical analysis is resolved as a variational problem of the effective potential for three kinds of background fields, namely, the complex scalar, and the two order parameters D and F of supersymmetry, the last one being treated perturbatively. We determine the stationary point and numerically check the consistency of such treatment as well as the local stability of the scalar potential. The coupling to the N=1 supergravity is given, and the gravitino mass formula is derived. © 2013 American Physical Society.

DOI： 10.1103/PhysRevD.88.025012

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In the context of the gauge-Higgs unification scenario in a 5-dimensional flat spacetime, we investigate Higgs boson production via gluon fusion and its diphoton decay mode at the LHC. We show that the signal strength of the Higgs diphoton decay mode observed at ATLAS and CMS, which is considerably larger than the Standard Model expectation, can be explained by a simple gauge-Higgs unification model with color-singlet bulk fermions to which a half-periodic boundary condition is assigned. The bulk fermions also play a crucial role in reproducing the observed Higgs boson mass around 125 GeV.

DOI： 10.1103/PhysRevD.87.095019

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In the context of the gauge-Higgs unification scenario in a 5-dimensional flat spacetime, we investigate Higgs boson production via gluon fusion and its diphoton decay mode at the LHC. We show that the signal strength of the Higgs diphoton decay mode observed at ATLAS and CMS, which is considerably larger than the Standard Model expectation, can be explained by a simple gauge-Higgs unification model with color-singlet bulk fermions to which a half-periodic boundary condition is assigned. The bulk fermions also play a crucial role in reproducing the observed Higgs boson mass around 125 GeV.

DOI： 10.1103/PhysRevD.87.095019

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We present the mechanism of the dynamical supersymmetry (SUSY) breaking at<br />
the metastable vacuum in the N=1 U(N) SUSY gauge theory with adjoint<br />
superfields. The dynamical SUSY breaking is triggered by the non-vanishing<br />
D-term coupled to the observable sector, and is realized by the self-consistent<br />
Hartree-Fock approximation of the NJL type while it eventually brings us the<br />
non-vanishing F-term as well. We numerically check the local stability of our<br />
metastable vacuum.

DOI： 10.1142/9789814566254_0030

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Under a few mild assumptions, N = 1 supersymmetry (SUSY) in four dimensions is shown to be spontaneously broken in a metastable vacuum in a self-consistent Hartree-Fock approximation of Bardeen-Cooper-Schrieffer/Nambu-Jona-Lasinio (BCS/NJL) type to the leading order, in the gauge theory specified by the gauge kinetic function and the superpotential of adjoint chiral superfields, in particular, that possess N = 2 extended SUSY spontaneously broken to N = 1 at tree level. We derive an explicit form of the gap equation, showing the existence of a nontrivial solution. The N = 2 gauginos in the observable sector receive mixed Majorana-Dirac masses and are split due to both the nonvanishing &lt; D-0 &gt; and &lt; F-0 &gt; induced with &lt; D-0 &gt;. It is argued that proper physical applications and assessment of the range of the validity of our framework are made possible by rendering the approximation into 1/N-2 expansion.

DOI： 10.1142/S0217751X1250159X

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We consider an N=1 supersymmetric U(N) gauge theory with an adjoint chiral<br />
multiplet. By developing a self-consistent Hartree-Fock approximation to the<br />
leading order which is reminiscent of that of the BCS/NJL in the<br />
superconductivity/chiral symmetry, we show that the N=1 supersymmetry is<br />
spontaneously broken, giving a mixed Majorana-Dirac mass term for gaugino due<br />
to the nonvanishing D-term VEV and F-term one induced by D-term.

DOI： 10.1142/S2010194513009392

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We discuss flavor mixing and resulting flavorchanging neutral current in a five-dimensional SU(3)(color) circle times SU(3) circle times U'(1) gauge-Higgs unification. Flavor mixing is realized by the fact that the bulk and brane-localized mass terms are not diagonalized simultaneously. As the concrete flavor-changing neutral current processes, we calculate the rate of B-d(0) - (B) over bar (0)(d) mixing and B-s(0) - (B) over bar (0)(s) mixing due to the exchange of nonzero Kaluza-Klein gluons at the tree level. We obtain a lower bound on the compactification scale of order O(TeV) by comparing our prediction on the mass difference of neutral B meson with the recent experimental data.

DOI： 10.1103/PhysRevD.85.096001

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We discuss flavor mixing and resulting Flavor Changing Neutral Current (FCNC) in the SU(3) circle times SU(3)(color) gauge-Higgs unification. As the FCNC process we calculate the rate of D-0 - (D) over bar (0) mixing due to the exchange of non-zero Kaluza-Klein gluons at the tree level. Flavor mixing is argued to be realized by the fact that the bulk mass term and brane localized mass term is not diagonalized simultaneously unless bulk masses are degenerate. It is shown that automatic suppression mechanism is operative for the FCNC processes of light quarks. We therefore obtain a lower bound on the compactification scale of order O(TeV) by comparing our prediction on the mass difference of neutral D meson with the recent experimental data, which is much milder than what we naively expect assuming only the decoupling of non-zero Kaluza-Klein gluons.

DOI： 10.1007/JHEP01(2012)047

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Gauge-Higgs unification is the fascinating scenario solving the hierarchy problem without supersymmetry. In this scenario, the Standard Model (SM) Higgs doublet is identified with extra component of the gauge field in higher dimensions and its mass becomes finite and stable under quantum corrections due to the higher dimensional gauge symmetry. On the other hand, Yukawa coupling is provided by the gauge coupling, which seems to mean that the flavor mixing and CP violation do not arise at it stands. In this talk, we discuss that the flavor mixing is originated from simultaneously non-diagonalizable bulk and brane mass matrices. Then, this mechanism is applied to various flavor changing neutral current (FCNC) processes via Kaluza-Klein (KK) gauge boson exchange at tree level and constraints for compactification scale are obtained.

DOI： 10.1063/1.4742112

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Gauge-Higgs unification is the fascinating scenario solving the hierarchy problem without supersymmetry. In this scenario, the Standard Model (SM) Higgs doublet is identified with extra component of the gauge field in higher dimensions and its mass becomes finite and stable under quantum corrections due to the higher dimensional gauge symmetry. On the other hand, Yukawa coupling is provided by the gauge coupling, which seems to mean that the flavor mixing and CP violation do not arise at it stands. In this talk, we discuss that the flavor mixing is originated from simultaneously non-diagonalizable bulk and brane mass matrices. Then, this mechanism is applied to various flavor changing neutral current (FCNC) processes via Kaluza-Klein (KK) gauge boson exchange at tree level and constraints for compactification scale are obtained.

DOI： 10.1063/1.4742112

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We discuss flavor mixing and resulting Flavor Changing Neutral Current (FCNC)
in a five dimensional SU(3)_color \otimes SU(3) \otimes U'(1) gauge-Higgs
unification. Flavor mixing is realized by the fact that the bulk and brane
localized mass terms are not diagonalized simultaneously. As the concrete FCNC
processes, we calculate the rate of B^0_d-\bar B^0_d mixing and B^0_s-\bar
B^0_s mixing due to the exchange of non-zero Kaluza-Klein gluons at the tree
level. We obtain a lower bound on the compactification scale of order O(TeV) by
comparing our prediction on the mass difference of neutral B meson with the
recent experimental data.

DOI： 10.1103/PhysRevD.85.096001

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We propose a new chiral model of metastable supersymmetry breaking in the<br />
conformal window via chiral/nonchiral Seiberg duality, which is focused on<br />
Spin(7)/SU(N_f-4) duality in this letter. Following the approach of<br />
Intriligator-Seiberg-Shih model, a small mass perturbation in the nonchiral<br />
theory leads to supersymmetry breaking by rank condition in the chiral dual<br />
description.

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We discuss flavor mixing and resulting Flavor Changing Neutral Current (FCNC)
in the SU(3) \otimes SU(3)_color gauge-Higgs unification. As the FCNC process
we calculate the rate of D^0-\bar D^0 mixing due to the exchange of non-zero
Kaluza-Klein gluons at the tree level. Flavor mixing is argued to be realized
by the fact that the bulk mass term and brane localized mass term is not
diagonalized simultaneously unless bulk masses are degenerate. It is shown that
automatic suppression mechanism is operative for the FCNC processes of light
quarks. We therefore obtain a lower bound on the compactification scale of
order \cal O(TeV) by comparing our prediction on the mass difference of neutral
D meson with the recent experimental data, which is much milder than what we
naively expect assuming only the decoupling of non-zero Kaluza-Klein gluons.

DOI： 10.1007/JHEP01(2012)047

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We discuss a muon anomalous magnetic moment in a five dimensional SU(3) gauge-Higs unification compactilied on M-4 x S-1 /Z(2) space-time including Z(2)-odd bulk mass for a fermion We calculate one-loop corrections to the anomalous magnetic moment of muon and find a lower bound for the compactification scale to be around 5 similar to 6 TeV by comparing nonzero Kaluza-Klein mode contributions with the muon (g - 2) experiment at BNL (C) 2010 Elsevier B V All rights reserved

DOI： 10.1016/j.nuclphysb.2010.06.001

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We propose a direct gauge mediation model based on an uplifted metastable supersymmetry (SUSY) breaking coupled to supergravity. A constant superpotential plays an essential role to fix the moduli as well as breaking SUSY and R symmetry and the cancellation of the cosmological constant. Gaugino masses are generated at leading order of SUSY breaking scale, and comparable to the sfermion masses as in the ordinary gauge mediation. The Landau pole problem for QCD coupling can be easily solved since more than half of messengers become superheavy, which are heavier than the grand unified theory (GUT) scale.

DOI： 10.1103/PhysRevD.82.075015

掲載種別：記事・総説・解説・論説等（学術雑誌）  

小林・益川両氏によって素粒子の標準模型における「CP対称性の破れ」の機構が提案され実験でも検証されたが,現在の物質・反物質の非対称性を十分に説明できない.本稿では,高次元理論に基づいた新しいCP対称性の破れの機構について最近の研究成果を解説する.

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We discuss flavor mixing and resultant flavor changing neutral current
processes in the SU(3) \otimes SU(3)_\text{color} gauge-Higgs unification
scenario. To achieve flavor violation is a challenging issue in the scenario,
since the Yukawa couplings are originally higher dimensional gauge
interactions. We argue that the presence of Z_2-odd bulk masses of fermions
plays a crucial role as the new source of flavor violation. Although
introducing brane-localized mass terms in addition to the bulk masses is
necessary to realize flavor mixing, if the bulk masses were universal among
generations, the flavor mixing and flavor changing neutral current processes
are known to disappear. We also discuss whether natural flavor conservation is
realized in the scenario. It is shown that the new source of flavor violation
leads to flavor changing neutral current processes at the tree level due to the
exchange of non-zero Kaluza-Klein gauge bosons. As a typical example we
calculate the rate of K^0 - \bar{K}^0 mixing due to the non-zero Kaluza-Klein
gluon exchange at the tree level. The obtained result for the mass difference
of neutral kaon is suppressed by the inverse powers of the compactification
scale. By comparing our prediction with the data we obtain the lower bound of
the compactification scale as a function of one unfixed parameter of the
theory, which is of {\cal O}(10) TeV, except for some extreme cases. We argue
that the reason to get such rather mild lower bound is the presence of
"GIM-like" mechanism, which is a genuine feature of GHU scenario.

DOI： 10.1007/JHEP11(2010)150

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We propose a new universal extra dimensional model that is defined on a six-dimensional spacetime which has a two-sphere orbifold S-2/Z(2) as an extra-space. We specify our model by choosing the gauge symmetry as SU(3) x SU(2) x U(1)(Y) x U(1)(X), introducing field contents in six dimensions as their zero modes correspond to the standard model particles, and determining a boundary condition of these fields on orbifold S-2/Z(2). A background gauge field that belongs to U(1)(X) is introduced there, which is necessary to obtain massless chiral fermions in four-dimensional spacetime. We then analyze Kaluza-Klein (KK) mode expansion of the fields in our model and derive the mass spectrum of the KK particles. We find that the lightest KK particles are the 1st KK particles of massless gauge bosons al. tree level. We also discuss the KK parity of the KK modes in our model and confirm the stability of the lightest KK particle which is important for dark matter physics. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nuclphysb.2009.11.023

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We discuss the modulus stabilization by the Casimir energy and various effects of IR-brane kinetic terms for the gauge fields in a gauge-Higgs unification model in the warped spacetime, where the Wilson line phase theta(H) is determined as theta(H) = pi/2. We find that the brane kinetic terms with O(1) coefficients are necessary for the modulus stabilization. On the other hand, large brane kinetic terms can deviate 4D gauge couplings from the standard model values and also cause too light Kaluza-Klein (KK) modes. In the parameter region that ensures the modulus stabilization, the KK gluon appears below 1TeV, which marginally satisfies the experimental bound. The allowed parameter region will be enlarged in a model where a smaller value of theta(H) is realized.

DOI： 10.1007/JHEP04(2010)100

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We address the challenging issue of how CP violation is realized in higher dimensional gauge theories without higher dimensional elementary scalar fields. In such theories interactions are basically governed by a gauge principle and therefore to get CP violating phases is a nontrivial task. It is demonstrated that CP violation is achieved as the result of compactification of extra dimensions, which is incompatible with the 4-dimensional CP transformation. As a simple example we adopt a 6-dimensional U(1) model compactified on a 2-dimensional orbifold T-2/Z(4). We argue that the 4-dimensional CP transformation is related to the complex structure of the extra space and show how the Z(4) orbifolding leads to CP violation. We confirm by explicit calculation of the interaction vertices that CP violating phases remain even after the rephasing of relevant fields. For completeness, we derive a rephasing invariant CP violating quantity, following a similar argument in the Kobayashi-Maskawa model which led to the Jarlskog parameter. As an example of a CP violating observable we briefly comment on the electric dipole moment of the electron.

DOI： 10.1103/PhysRevD.81.076006

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We investigate Higgs boson production process via gluon fusion at LHC in our six-dimensional universal extra dimension model compactified on a spherical orbifold S (2)/Z (2). We find a striking result that the Higgs production cross section in our model is predicted to have 30(10)% enhancement compared to the predictions of the Standard Model (the minimal universal extra dimension model) for the compactification scale of order 1 TeV.

DOI： 10.1140/epjc/s10052-010-1236-3

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Higgs boson production by the gluon fusion and its decay into two photons at<br />
the LHC are investigated in the context of the gauge-Higgs unification<br />
scenario. The qualitative behaviors for these processes in the scenario are<br />
quite distinguishable from those of the Standard Model and the universal extra<br />
dimension scenario because of the overall sign difference for the effective<br />
couplings induced by one-loop corrections through Kaluza-Klein modes.

DOI： 10.1142/9789814329521_0017

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We address the challenging issue of how CP violation is realized in higher
dimensional gauge theories without higher dimensional elementary scalar fields.
In such theories interactions are basically governed by a gauge principle and
therefore to get CP violating phases is a non-trivial task. It is demonstrated
that CP violation is achieved as the result of compactification of extra
dimensions, which is incompatible with the 4-dimensional CP transformation. As
a simple example we adopt a 6-dimensional U(1) model compactified on a
2-dimensional orbifold $T^{2}/Z_{4}$. We argue that the 4-dimensional CP
transformation is related to the complex structure of the extra space and show
how the $Z_{4}$ orbifolding leads to CP violation. We confirm by explicit
calculation of the interaction vertices that CP violating phases remain even
after the re-phasing of relevant fields. For completeness, we derive a
re-phasing invariant CP violating quantity, following a similar argument in the
Kobayashi-Maskawa model which led to the Jarlskog parameter. As an example of a
CP violating observable we briefly comment on the electric dipole moment of the
electron.

DOI： 10.1103/PhysRevD.81.076006

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study the neutron electric dipole moment (EDM) in a five-dimensional SU(3) gauge-Higgs unification compactified on M-4 x S-1/Z(2) space-time including a massive fermion. We point out that to realize the CP violation is a nontrivial task in the gauge-Higgs unification scenario and argue how the CP symmetry is broken spontaneously by the vacuum expectation value of the Higgs, the extra space component of the gauge field. We emphasize the importance of the interplay between the vacuum expectation value of the Higgs and the Z(2)-odd bulk mass term to get physically the CP violation. We then calculate the one-loop contributions to the neutron EDM as the typical example of the CP violating observable and find that the EDM appears already at the one-loop level, without invoking the three-generation scheme. We then derive a lower bound for the compactification scale, which is around 2.6 TeV, by comparing the contribution due to the nonzero Kaluza-Klein modes with the experimental data.

DOI： 10.1103/PhysRevD.80.055025

掲載種別：書評論文，書評，文献紹介等  

In this manuscript, a unified approach to hadron physics from the holographic point of view is described. After the introduction of a general setup for the meson nucleon system based on the bottom-up approach of QCD (AdS/QCD), as an illustration, we specifically examine meson-nucleon couplings. This is an example of the notion we call "holographic unification" in hadron physics.

DOI： 10.1140/epjc/s10052-009-1096-x

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We study the neutron electric dipole moment (EDM) in a five dimensional SU(3)
gauge-Higgs unification compactified on M^4 \times S^1/Z_2 space-time including
a massive fermion. We point out that to realize the CP violation is a
non-trivial task in the gauge-Higgs unification scenario and argue how the CP
symmetry is broken spontaneously by the VEV of the Higgs, the extra space
component of the gauge field. We emphasize the importance of the interplay
between the VEV of the Higgs and the Z_2-odd bulk mass term to get physically
the CP violation. We then calculate the one-loop contributions to the neutron
EDM as the typical example of the CP violating observable and find that the EDM
appears already at the one-loop level, without invoking to the three generation
scheme. We then derive a lower bound for the compactification scale, which is
around 2.6 TeV, by comparing the contribution due to the nonzero Kaluza-Klein
modes with the experimental data.

DOI： 10.1103/PhysRevD.80.055025

掲載種別：記事・総説・解説・論説等（学術雑誌）  

In this manuscript, a unified approach to hadron physics from holographic
point of view is described. After introduction of a general setup for
meson-nucleon system based on the bottom-up approach of QCD (AdS/QCD), as an
illustration, we specifically examine meson-nucleon couplings. This is an
example of the notion we call "holographic unification" in hadron physics.

DOI： 10.1140/epjc/s10052-009-1096-x

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We propose a new Universal Extra Dimensional model that is defined on a
six-dimensional spacetime which has a two-sphere orbifold $S^2/Z_2$ as an
extra-space. We specify our model by choosing the gauge symmetry as
SU(3)$\timesSU(2)\timesU(1)_Y \timesU(1)_X$, introducing field contents in
six-dimensions as their zero modes correspond to the Standard model particles,
and determining a boundary condition of these fields on orbifold $S^2/Z_2$. A
background gauge field that belongs to U(1)$_X$ is introduced there, which is
necessary to obtain massless chiral fermions in four-dimensional spacetime. We
then analyze Kaluza-Klein(KK) mode expansion of the fields in our model and
derive the mass spectrum of the KK particles. We find that the lightest KK
particles are the 1st KK particle of massless gauge bosons at tree level. We
also discuss the KK parity of the KK modes in our model and confirm the
stability of the lightest KK particle which is important for dark matter
physics.

DOI： 10.1016/j.nuclphysb.2009.11.023

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We find that the one-loop correction to the ratio of Yukawa coupling and<br />
gauge coupling in the gauge-Higgs unification, &quot;gauge-Yukawa universality<br />
violation&quot;, is finite and calculable in any space-time dimension. Applying this<br />
result to the ratio of top quark and W-boson masses, we show that the order one<br />
correction required to generate a viable top quark mass is indeed possible if<br />
the fermion embedding top quark belongs to the large dimensional representation<br />
of the gauge group and a vacuum expectation value of Higgs scalar field is very<br />
small comparing to the compactification scale.

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We discuss the anomalous magnetic moment of fermion in a realistic SU(3) model of gauge-Higgs unification compactified on an orbifold S-1/Z(2) including Z(2)-odd bulk mass for fermions. An operator analysis implies that the anomalous magnetic moment should be finite and predictable, even though higher dimensional gauge theories are nonrenormalizable. Our main purpose is to clarify the cancellation mechanism of the UV divergences appearing in various types of Feynman diagrams. The cancellation of divergence turns out to take place between the contributions of the partners in the Higgs-like mechanism present in the nonzero Kaluza-Klein modes to form massive gauge bosons. It is also argued that the cancellation may be attributed to the quantum mechanical supersymmetry hidden in the scenario of gauge-Higgs unification.

DOI： 10.1103/PhysRevD.79.075018

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We show that the gluon fusion amplitude in the gauge-Higgs unification scenario is finite in any dimension regardless of its nonrenormalizability. This result is supported by the fact that the local operator describing the gluon fusion process is forbidden by the higher dimensional gauge invariance. We explicitly calculate the gluon fusion amplitude in an arbitrary dimensional gauge-Higgs unification model and indeed obtain the finite result. © 2008 World Scientific Publishing Company.

DOI： 10.1142/S0217732308028247

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We calculate one-loop radiative correction to the mass of Higgs identified with the extra space components of the gauge field in a six-dimensional massive scalar QED compactified on a two-sphere. The radiatively induced Higgs mass is explicitly shown to be finite for arbitrary bulk scalar mass M. Furthermore, the remaining finite part also turns out to vanish, at least for the case of small M, thus suggesting that the radiatively induced Higgs mass exactly vanishes, in general. The non-zero "Kaluza-Klein" modes in the gauge sector are argued to have a Higgs-like mechanism and quantum mechanical N = 2 supersymmetry, while the Higgs zero modes, as supersymmetric states, have a close relation with monopole configuration.

DOI： 10.1143/JPSJ.77.074101

掲載種別：記事・総説・解説・論説等（学術雑誌）   共著区分：単著  

We show that the gluon fusion amplitude in the gauge-Higgs unification
scenario is finite in any dimension regardless of its nonrenormalizability.
This result is supported by the fact that the local operator describing the
gluon fusion process is forbidden by the higher dimensional gauge invariance.
We explicitly calculate the gluon fusion amplitude in an arbitrary dimensional
gauge-Higgs unification model and indeed obtain the finite result.

DOI： 10.1142/S0217732308028247

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

The Higgs boson production by the gluon fusion and its decay into two photons at the LHC are investigated in the context of the gauge-Higgs unification scenario. The qualitative behaviors for these processes in the gauge-Higgs unification are quite distinguishable from those of the standard model and the universal extra dimension scenario because of the overall sign difference for the effective couplings induced by one-loop corrections through the Kaluza-Klein modes. For the Kaluza-Klein mode mass smaller than 1 TeV, the Higgs production cross section and its branching ratio into two photons are sizably deviated from those in the standard model. Associated with the discovery of the Higgs boson, this deviation may be measured at the LHC.

DOI： 10.1103/PhysRevD.77.055010

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）   共著区分：単著  

In this talk, we discuss an attempt to construct a realistic model of the
grand gauge-Higgs unification. We investigate a 5D SU(6) grand gauge-Higgs
unification model compactified on an orbifold S^1/Z_2. Ordinary quarks and
leptons, together with right-handed neutrinos, are just accommodated into a
minimal set of representations of the gauge group, without introducing any
exotic states in the same representations. The proton decay turns out to be
forbidden at least at the tree level. We also find a correct electroweak
symmetry breaking SU(2)_L \times U(1)_Y \to U(1)_{em} is easily realized by
introducing suitable number of adjoint fermions.

DOI： 10.1063/1.2939048

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We present a very simple model of the radius stabilization in a supersymmetric (SUSY) Randall-Sundrum model with a hypermultiplet and a boundary constant superpotential. A wide range of parameters where the anomaly mediation of SUSY breaking is dominated is found although there are many problematic bulk effects of SUSY breaking. A negative cosmological constant in the radius stabilized vacuum can be cancelled by a localized SUSY breaking. Making use of this localized SUSY breaking also solves the mu-problem by Giudice-Masiero mechanism.

DOI： 10.1063/1.3051971

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

In this talk, we discuss an attempt to construct a realistic model of the grand gauge-Higgs unification. We investigate a 5D SU(6) grand gauge-Higgs unification model compactified on an orbifold S-1/Z(2). Ordinary quarks and leptons, together with right-banded neutrinos, are just accommodated into a minimal set of representations of the gauge group, without introducing any exotic states in the same representations. The proton decay turns out to be forbidden at least at the tree level. We also find a correct electroweak symmetry breaking SU(2)(L) x U(1)(Y)-&gt; U(1)(em) is easily realized by introducing suitable number of adjoint fermions.

DOI： 10.1063/1.2939048

掲載種別：記事・総説・解説・論説等（学術雑誌）  

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 × S1 and determine the mass and potential of a 4D Higgs field (the A5, component) at the two loop level with gauge invariant regularization. It is seen that the mass is free from divergences and independent of the renormalization scheme.

DOI： 10.1143/PTP.118.1053

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We construct a model of direct gauge mediation of metastable supersymmetry breaking by simply deforming the Intriligator, Seiberg, and Shih model in terms of a dual meson superpotential mass term. No extra matter field is introduced. The deformation explicitly breaks a U(1)(R) symmetry and pseudomoduli have a nonzero VEV at one-loop. Our metastable supersymmetry breaking vacuum turns out to be sufficiently long-lived. By gauging a subgroup of flavor symmetry, our model can directly couple to the standard model, which leads to nonvanishing gaugino mass generation. It is also shown that our model can evade the Landau pole problem. We show the parameters in the supersymmetry breaking sector are phenomenologically constrained.

DOI： 10.1103/PhysRevD.76.115019

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

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 × S1 and determine the mass and potential of a 4D Higgs field (the A5, component) at the two loop level with gauge invariant regularization. It is seen that the mass is free from divergences and independent of the renormalization scheme.

DOI： 10.1143/PTP.118.1053

掲載種別：記事・総説・解説・論説等（学術雑誌）  

Higgs boson production by the gluon fusion and its decay into two photons at
the LHC are investigated in the context of the gauge-Higgs unification
scenario. The qualitative behaviors for these processes in the gauge-Higgs
unification are quite distinguishable from those of the Standard Model and the
universal extra dimension scenario because of the overall sign difference for
the effective couplings induced by one-loop corrections through Kaluza-Klein
(KK) modes. For the KK mode mass smaller than 1 TeV, the Higgs productions
cross section and its branching ratio into two photons are sizably deviated
from those in the Standard Model. Associated with the discovery of Higgs boson,
this deviation may be measured at the LHC.

DOI： 10.1103/PhysRevD.77.055010

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Supersymmetry breaking and radius stabilization by constant superpotentials<br />
localized at boundaries is studied in a supersymmetric warped space model where<br />
a hypermultiplet, a compensator and a radion multiplet are taken into account.<br />
Soft mass induced by the anomaly mediation can be of the order of 100GeV and<br />
can be dominant compared to that mediated by bulk fields. A lighter physical<br />
mode composed of the radion and the moduli can have mass of the order of a TeV<br />
and the gravitino mass can be of the order of 10^7 GeV. The radius is<br />
stabilized by the presence of the constant boundary superpotentials. We also<br />
find that the mass splitting has an interesting dependence on the bulk mass<br />
parameter c.

DOI： 10.1103/PhysRevD.74.045017

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We show that the anomalous magnetic moment of fermion in the gauge-Higgs unification is finite in any spacetime dimensions, which is a new predictive physical observable similar to the Higgs mass.

DOI： 10.1103/PhysRevD.76.075009

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We show that the anomalous magnetic moment of fermion in the gauge-Higgs
unification is finite in any spacetime dimensions, which is a new predictive
physical observable similar to the Higgs mass.

DOI： 10.1103/PhysRevD.76.075009

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We investigate the one-loop contributions to S and T oblique parameters in gauge-Higgs unification. We show that these parameters are finite in five dimensional space-time, but are divergent in more than five dimensions. Remarkably, however, we find that a particular linear combination of S and T parameters, S-4cos θWT, becomes finite for six dimensional space-time, though each of these parameters are divergent. This is because, in the gauge-Higgs unification scenario, the operators relevant for S and T parameters are not independent, but are included in a unique higher dimensional gauge invariant operator. Thus the predictable linear combination is model independent, irrespective of the detail of the matter content. © 2007 The American Physical Society.

DOI： 10.1103/PhysRevD.75.115011

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We investigate a 5D SU(6) grand gauge-Higgs unification model compactified on
an orbifold S^1/Z_2. Ordinary quarks and leptons, together with right-handed
neutrinos, are just accommodated into a minimal set of representations of the
gauge group, without introducing any exotic states. The proton decay turns out
to be forbidden at least at the tree level. We also find a correct electroweak
symmetry breaking SU(2)_L \times U(1)_Y \to U(1)_{em} is easily realized by
introducing suitable number of adjoint fermions.

DOI： 10.1016/j.physletb.2007.07.053

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We investigate a 5D SU(6) grand gauge-Higgs unification model compactified on<br />
an orbifold S^1/Z_2. Ordinary quarks and leptons, together with right-handed<br />
neutrinos, are just accommodated into a minimal set of representations of the<br />
gauge group, without introducing any exotic states. The proton decay turns out<br />
to be forbidden at least at the tree level. We also find a correct electroweak<br />
symmetry breaking SU(2)_L \times U(1)_Y \to U(1)_{em} is easily realized by<br />
introducing suitable number of adjoint fermions.

DOI： 10.1016/j.physletb.2007.07.053

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

A warped space model with a constant boundary superpotential has been an efficient model both to break supersymmetry and to stabilize the radius, when a hypermultiplet, a compensator, and a radion multiplet are taken into account. In such a model of radius stabilization, the radion and moduli masses, the gravitino mass, and the induced soft masses are studied. We find that a lighter physical mode composed of the radion and the moduli can have mass of the order of a TeV and that the gravitino mass can be of the order of 10(7) GeV. It is also shown that soft mass induced by the anomaly mediation can be of the order of 100 GeV and can be dominant compared to that mediated by bulk fields. Localized F-terms and D-terms are discussed as candidates for canceling the cosmological constant. We find that there is no flavor changing neutral current problem in a wide range of parameters.

DOI： 10.1103/PhysRevD.75.125014

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We investigate the divergence structure of one-loop corrections to S and T<br />
parameteres in gauge-Higgs unification. We show that these parameters are<br />
finite in five dimensions, but divergent in more than five dimensions.<br />
Remarkably, a particular linear combination of S and T parameters becomes<br />
finite in six dimension case, which is indicated from the operator analysis in<br />
a model independent way.

DOI： 10.1142/9789812790750_0039

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

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 detail how the divergences are exactly canceled and the mass becomes finite. The key ingredients to obtain the result are the shift symmetry and the Ward-Takahashi identity. We also evaluate the finite part of corrections. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nuclphysb.2006.07.023

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Supersymmetry breaking by constant (field independent) superpotentials localized at boundaries is studied in a supersymmetric warped space model. We calculate the Kaluza-Klein mass spectrum of the hypermultiplet. We take into account of the radion and the compensator supermultiplets, as well as the bulk mass c for the hypermultiplet. The mass splitting is similar to that of the Scherk-Schwarz supersymmetry breaking (in flat space) for large vertical bar c vertical bar, and has an interesting dependence on the bulk mass parameter c. We show that the radius is stabilized by the presence of the constant boundary superpotentials.

DOI： 10.1103/PhysRevD.74.045017

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We study the bulk mass effects on the electroweak phase transition at finite
temperature in a five dimensional SU(3) gauge-Higgs unification model on an
orbifold. We investigate whether the Higgs mass satisfying the experimental
lower bound can be compatible with the strong first order phase transition
necessary for a successful electroweak baryogenesis. Our numerical results show
that the above statement can be realized by matter with bulk mass yielding a
viable Higgs mass. We also find an interesting case where the heavier Higgs
gives the stronger first order phase transition.

DOI： 10.1103/PhysRevD.74.015017

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study effects of bulk mass on electroweak symmetry breaking and Higgs mass in the scenario of five-dimensional SU(3) gauge-Higgs unification defined on M(4) x S(1)/Z(2). The asymptotic form of effective potential for the Higgs field is obtained, from which a transparent and useful expression for the Higgs mass is found. The small vacuum expectation values (VEV) for Higgs field can be realized by choosing bulk mass parameters appropriately for a fixed set of matter content. The bulk mass for periodic fermion field, in general, has effects to make the Higgs mass less heavy. On the other hand, the bulk mass for antiperiodic field does not directly affect the Higgs mass, but it contributes to increase or decrease the Higgs mass, depending on how small the VEV is induced due to the antiperiodic field. We give numerical examples to confirm these effects, in which the role of the bulk mass is also definitely clear. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physletb.2006.04.044

掲載種別：記事・総説・解説・論説等（学術雑誌）  

We study effects of bulk mass on electroweak symmetry breaking and Higgs mass
in the scenario of five dimensional SU(3) gauge-Higgs unification defined on
M^4\times S^1/Z_2. The asymptotic form of effective potential for the Higgs
field is obtained, from which a transparent and useful expression for the Higgs
mass is found. The small vacuum expectation values (VEV) for Higgs field can be
realized by choosing bulk mass parameters approriately for a fixed set of
matter content. The bulk mass for periodic fermion field, in general, has
effects to make the Higgs mass less heavy. On the other hand, the bulk mass for
antiperiodic field does not directly affect the Higgs mass, but it contributes
to increase or decrease the Higgs mass, depending on how small the VEV is
induced due to the antiperiodic field. We give numerical examples to confirm
these effects, in which the role of the bulk mass is also definitely clear.

DOI： 10.1016/j.physletb.2006.04.044

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

Several physical quantities of light hadrons are examined by a new holographic model of QCD, which is the modified version of the one proposed by Erlich et al. defined on AdS(5). In our model, AdS(5) is deformed by a non-trivial bulk scalar, this is corresponding to adding the mass term of the adjoint fermions to the 4d SYM theory dual to the gravity on AdS(5). We find that this deformation should be taken to be rather small, but its important effects are also seen. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physletb.2005.12.004

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study the bulk mass effects on the electroweak phase transition at finite temperature in a five-dimensional SU(3) gauge-Higgs unification model on an orbifold. We investigate whether the Higgs mass satisfying the experimental lower bound can be compatible with the strong first order phase transition necessary for a successful electroweak baryogenesis. Our numerical results show that the above statement can be realized by matter with bulk mass yielding a viable Higgs mass. We also find an interesting case where the heavier Higgs gives the stronger first order phase transition. © 2006 The American Physical Society.

DOI： 10.1103/PhysRevD.74.015017

掲載種別：記事・総説・解説・論説等（学術雑誌）  

Several physical quantities of light hadrons are examined by a new
holographic model of QCD, which is the modified version of the one proposed by
Erlich et al. defined on AdS${}_5$. In our model, AdS${}_5$ is deformed by a
non-trivial bulk scalar, this is corresponding to adding the mass term of the
adjoint fermions to the 4d SYM theory dual to the gravity on AdS${}_5$. We find
that this deformation should be taken to be rather small, but its important
effects are also seen.

DOI： 10.1016/j.physletb.2005.12.004

掲載種別：記事・総説・解説・論説等（学術雑誌）  

CiNii Article

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

A supersymmetric composite model of color superconductivity is proposed. Quarks and diquarks are dynamically generated as composite fields by a newly introduced strong gauge dynamics. It is shown that the condensation of the scalar component of the diquark supermultiplet occurs when the chemical potential becomes larger than some critical value. We believe that the model captures well the aspects of the diquark condensate behavior and helps in understanding the diquark dynamics in real QCD. The results obtained here might be useful when we consider a theory composed of quarks and diquarks. © World Scientific Publishing Company.

DOI： 10.1142/S021773230501786X

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

We study the phase transition in gauge-Higgs unification at finite<br />
temperature. In particular, we obtain the strong first order electroweak phase<br />
transition for a simple matter content yielding the correct order of Higgs mass<br />
at zero temperature. Two stage phase transition is found for a particular<br />
matter content, which is the strong first order at each stage. We further study<br />
supersymmetric gauge models with the Scherk-Schwarz supersymmetry breaking. We<br />
again observe the first order electroweak phase transition and multi stage<br />
phase transition.

DOI： 10.1103/PhysRevD.72.046003

掲載種別：記事・総説・解説・論説等（学術雑誌）  

The structure of Yukawa coupling matrices is investigated in type IIA T-6/(Z(2) x Z(2)) orientifold models with intersecting D-branes. Yukawa coupling matrices are difficult to be made realistic in conventional models in which the generation structure emerges by the multiple intersection of D-branes in the factorized T-6 = T-2 x T-2 x T-2. We study the new type of favor structure, where Yukawa couplings are dynamically generated, and show this type of models lead to non-trivial structures of Yukawa coupling matrices, which can be realistic.

DOI： 10.1140/epjc/s2005-02166-4

掲載種別：機関テクニカルレポート，技術報告書，プレプリント等  

The structure of Yukawa coupling matrices is investigated in type IIA T-6/(Z(2) x Z(2)) orientifold models with intersecting D-branes. Yukawa coupling matrices are difficult to be made realistic in conventional models in which the generation structure emerges by the multiple intersection of D-branes in the factorized T-6 = T-2 x T-2 x T-2. We study the new type of favor structure, where Yukawa couplings are dynamically generated, and show this type of models lead to non-trivial structures of Yukawa coupling matrices, which can be realistic.

DOI： 10.1140/epjc/s2005-02166-4

掲載種別：記事・総説・解説・論説等（学術雑誌）  

DOI： 10.1142/S021773230501786X

CiNii Article

その他URL： http://arxiv.org/pdf/hep-ph/0411079v2

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