Proton decay is one of the most important predictions of the grand unified
theory (GUT). In the supersymmetric (SUSY) GUT, proton decays via the
dimension-five operators need to be suppressed. In the model where
${\bf 10}+\overline{\bf 12...

We explain the 2.3 sigma deviation in the recent measurements of the neutral
B mesons decay into muon pairs from the standard model prediction in the
framework of supersymmetric grand unified models using anti-symmetric coupling
as a new source of...

Higgs cubic coupling plays a crucial role to probe an origin of electroweak
symmetry breaking. It is expected that the cubic coupling is measured by Higgs
pair production at the LHC and ILC, and the deviations from the standard model
can be extrac...

We consider the Yukawa couplings for quarks and leptons in the context of
Pati-Salam model using intersecting D-brane models where the Yukawa coupling
matrices are rank one in a simple choice of family replication. The CKM mixings
can be explained...

We show that in a class of minimal supersymmetric SO(10) models which have
been found to be quite successful in predicting neutrino mixings, all proton
decay modes can be suppressed by a particular choice of Yukawa textures. This
suppression works...

We present a model in which elementary particles and forces are unified in
the framework of quantum field theory in higher dimensions. The particles
include gauge bosons, quarks and leptons, as well as the Higgs bosons and the
forces include stron...

We discuss the Yukawa coupling unification, a very interesting prediction of
the grand unified theory, in the context of scenarios with more than one pair
of Higgs doublet since the current LHC constraint has become a problem for the
Yukawa unific...

The nearly right unitarity triangle can be simply obtained if a quark mass
matrix is written as a linear combination of real rank-1 matrices and the
coefficient which gives the mass of the second generation is pure imaginary.
Supposing that the so...

The absence of any signal of supersymmetry (SUSY) at the LHC has raised the
SUSY particle mass scale compared to boson mass . We investigate the
naturalness of the electroweak symmetry breaking after considering radiative
symmetry breakin...

Supersymmetric grand unified models with renormalizable Yukawa
couplings involving only and Higgs fields have
been shown to realize the fermion masses and mixings economically. In previous
works, the sum ru...

Kazunori Kohri, C. S. Lim, Chia-Min Lin, Yukihiro Mimura

Sep 2013

In this paper, we consider high scale (100 TeV) supersymmetry (SUSY) breaking
and realize the idea of hilltop supernatural inflation in concrete particle
physics models based on flipped-SU(5) and Pati-Salam models in the framework of
supersymmetri...

Bhaskar Dutta, Yukihiro Mimura, Rabindra N. Mohapatra

Feb 2013

Supersymmetric SO(10) grand unified models with renormalizable Yukawa
couplings involving {\bf 10}, {\bf 126} and {\bf 120} Higgs fields have been
shown to give a very economical theory for understanding quark-lepton flavor in
a unified framework....

We investigate a possibility if a loop diagram via Higgsino can enhance the
Higgs to diphoton decay width in supersymmetric models with an extension of
Higgs sector. A model with an additional non-renormalizable term of Higgs
fields is firstly ana...

A Higgs-like new boson with mass around 126 GeV is now established, but its
true nature probably cannot be settled with 2011--2012 LHC data. We assume it
is a dilaton with couplings weaker than the Higgs boson (except to
and ), ...

We suggest natural TeV-scale seesaw with non-negligible left-right neutrino
mixings as preserving tiny neutrino masses. Our analysis is exhibited, without
loss of generality, by taking a basis of the neutrino matrices, in which the
condition to ob...

We investigate the recent CDF measurement of the Br(B_s --> mu+mu-) which
shows excess over the Standard Model. We consider minimal supergravity
motivated models (mSUGRA)/CMSSM and grand unified models, SU(5) and SO(10). In
the grand unified model...

The recent data on dijet excess reported by CDF may be interpreted as the
associated production of a and a new particle of mass about 150 GeV which
subsequently decays into two hadron jets. We study the possibility of
explaining the di...

We analyze the puzzle of the dimuon CP asymmetry in B_s decays in two Higgs
doublet models. We show that the flavor changing neutral current (FCNC) induced
by the Higgs coupling in a type III two Higgs doublet model provides a solution
to the dimu...

Ilia Gogoladze, Rizwan Khalid, Yukihiro Mimura, Qaisar Shafi

Phys.Rev.D83:095007,2011 Dec 2010

If the lightest dark matter neutralino has a sufficiently large Higgsino
component, its spin-independent and spin-dependent cross sections on nucleons
can be sizable enough to be detected soon in direct and indirect surveys. We
outline in this pap...

We investigate the effect of the dimuon CP asymmetry from the B decay modes,
recently observed at 3.2 sigma deviation from the Standard Model (SM) by the D0
collaboration, in the context of SU(5) and SO(10) GUT models. We exhibit that a
large amou...

Ilia Gogoladze, Yukihiro Mimura, Nobuchika Okada, Qaisar Shafi

Jan 2010

We consider a class of supersymmetric models containing baryon number
violating processes such as observable neutron - antineutron oscillations that
are mediated by color triplet diquark fields. For plausible values of the
diquark-quark couplings,...

We present a supersymmetric SO(10) grand unified theory (GUT) of flavor based
on an family symmetry. It makes use of our recent proposal to use SO(10)
with type II seesaw mechanism for neutrino masses combined with a simple ansatz
that the d...

M. Adeel Ajaib, I. Gogoladze, Yukihiro Mimura, Q. Shafi

Phys.Rev.D80:125026,2009 Oct 2009

We explore extensions of the MSSM in which TeV scale vector-like multiplets
can mediate observable n-anti-n oscillations, without causing conflict with the
proton decay experiments, with a U(1) symmetry playing an important role. The
colored vecto...

Diverse mass and mixing patterns between the quarks and leptons makes it
challenging to construct a simple grand unified theory of flavor. We show that
SO(10) SUSY GUTs with type II seesaw mechanism giving neutrino masses provide a
natural framewo...

We combine the analyses for flavor changing neutral current processes and
dark matter solutions in minimal-type supersymmetric grand unified theory (GUT)
models, SO(10) and SU(5), with a large B_s - anti-B_s mixing phase and large
tan beta. For la...

We construct an orbifold model in which all the standard model particles are
unified in a gauge multiplet in higher dimensional supersymmetric gauge theory.
We find that a flavor symmetry has to remain in four dimensions due to the
discrete charge...

In orbifold models, gauge, Higgs and the matter fields can be unified in one
multiplet from the compactification of higher dimensional supersymmetric gauge
theory. We study how three families of chiral fermions can be unified in the
gauge multiple...

We investigate the possibility of a large B_s-\bar B_s mixing phase in the
context of grand unified theory (GUT) models, e.g., SO(10) and SU(5). In these
models, we find that a large phase of B_s mixing is correlated with Br(b -> s
gamma), Br(tau ...

We consider the possibility of a large phase of B_s-\bar B_s mixing in
supersymmetric SU(5) and SO(10) models. We find that in the SU(5) model, the
magnitude of this phase is correlated with the branching ratio of \tau ->
\mu\gamma and the phase c...

Discovery of neutrino mass has put the spotlight on supersymmetric SO(10) as
a natural candidate for grand unification of forces and matter. However, the
suppression of proton decay is a major problem in any supersymmetric grand
unified models. In...

We study the constraint arising from the recently observed D - anti-D mixing
in the context of supersymmetric models with left-right symmetry. In these
models, the supersymmetric contributions in the mixing amplitudes of D -
anti-D, K - anti-K and...

Bhaskar Dutta, Yukihiro Mimura, Dimitri V. Nanopoulos

Phys.Lett.B656:199-206,2007 May 2007

We show that the little hierarchy problem can be solved in the no-scale
supergravity framework. In this model the supersymmetry breaking scale is
generated when the electroweak symmetry breaking condition is satisfied and
therefore, unlike usual s...

Ilia Gogoladze, Chin-Aik Lee, Yukihiro Mimura, Qaisar Shafi

Phys.Lett.B649:212-217,2007 Mar 2007

We discuss how unification of the gauge, Higgs and (three chiral family)
matter superfields can be realized from the compactification of a six
dimensional supersymmetric SU(8) gauge theory over the orbifold R^4 x T^2/Z_3.
The bulk gauge interactio...

We investigate the little hierarchy between Z boson mass and the SUSY
breaking scale in the context of landscape of electroweak symmetry breaking
vacua. We consider the radiative symmetry breaking and found that the scale
where the electroweak sym...

Recently, a more than 2sigma discrepancy has been observed between the well
measured inclusive value of Vub and the predicted value of Vub from the
unitarity triangle fit using the world average value of sin2beta. We attempt to
resolve this tensio...

We study B_s-\bar{B}_s mixing in grand unified SO(10), SU(5) models where the
mixings among the second and third generation squarks arise due to the
existence of flavor violating sources in the Dirac and Majorana couplings which
are responsible fo...

We investigate lepton flavor violation in the context of intersecting D-brane
models. We point out that these models have a source to generate flavor
violation in the trilinear scalar couplings while the geometry of the
construction leads to degen...

We discuss a realistic high scale ( GeV) supersymmetric
seesaw model based on the gauge group
where neutron-anti-neutron oscillation can occur at an observable rate. This is
contrary to the...

During the past year, a minimal renormalizable supersymmetric SO(10) model
has been proposed with the following properties: it predicts a naturally stable
dark matter and neutrino mixing angles theta_atm and theta_13 while at the same
time accommo...

Ilia Gogoladze, Tianjun Li, Yukihiro Mimura, S. Nandi

Phys.Rev. D72 (2005) 055006 Apr 2005

Supersymmetric gauge theories, in higher dimensions compactified in an
orbifold, give a natural framework to unify the gauge bosons, Higgs fields and
even the matter fields in a single multiplet of the unifying gauge symmetry.
The extra dimensions...

In the context of split supersymmetry, the gaugino mass spectrum seems to be
very important to satisfy the dark matter content of the universe and the gauge
coupling unification. In this paper, we have considered various sources of
gaugino masses ...

Ilia Gogoladze, Tianjun Li, Yukihiro Mimura, S. Nandi

Phys.Lett.B622:320-326,2005 Jan 2005

We present an orbifold GUT model in which the NMSSM Higgs trilinear couplings
are unified with the three Standard Model gauge couplings. The model is
constructed as an N=2 supersymmetric SU(8) gauge theory in six dimensions,
which is reduced to th...

It has recently been shown that a minimal SO(10) model with a single {\bf 10}
and single {\bf 126} Higgs field breaking B-L symmetry predicts large solar and
atmospheric mixings in agreement with observations if it is assumed that the
neutrino mas...

A minimal supersymmetric SO(10) model with one {\bf 10} and one {\bf 126}
Higgs superfield has recently been shown to predict all neutrino mixings as
well as the solar mass difference squared in agreement with observations. Two
assumptions critica...

In supersymmetric theories with extra dimensions, the Higgs and matter fields
can be part of the gauge multiplet, so that the Yukawa interactions can arise
from the gauge interactions. This leads to the possibility of gauge-Yukawa
coupling unifica...

Ilia Gogoladze, Yukihiro Mimura, S. Nandi, Kazuhiro Tobe

Phys.Lett. B575 (2003) 66-74 Aug 2003

Recently it has been proposed that, in the framework of quantum field theory,
both the Standard Model gauge and Yukawa interactions arise from a single gauge
interaction in higher dimensions with supersymmetry. This leads to the
unification of the...

We consider the unification of gauge, Higgs as well as the matter fields in a
6D N=2 supersymmetric SU(8) gauge theory. The gauge symmetry SU(8) is broken
down to SU(4) x SU(2)_L x SU(2)_R x U(1)^2 in 4D through T^2/Z_6 orbifold
compactification, ...

We construct a supersymmetric left-right model in four dimension with
gauge-Higgs unification starting from a SU(3)_c x SU(4)_w x U(1)_{B-L} gauge
symmetry in five dimension. The model has several interesting features, such
as, the CKM mixings in ...

We study the five dimensional SU(3)_c \times SU(3)_L \times U(1)_X gauge
theory (3-3-1 Model) in which the gauge symmetry is broken down through
orbifold compactification to four dimensions. The new model has several
distinguishing features compar...

We study the five dimensional left-right symmetric gauge theory in which the
gauge symmetry is broken down through orbifold compactification to four
dimensions. The right handed charged gauge boson, W_R is a Kaluza-Klein excited
state in this mode...

We suggest a solution to the \mu problem of gauge mediated supersymmtery
breaking models based on flavor symmetries. In this scenario the \mu term
arises through the vacuum expectation value of a singlet scalar field which is
suppressed by a flavo...

We construct a model with a SU(3) X U(1) horizontal symmetry in the context
of Grand Unified Theories. In our models, the bi-maximal lepton mixing and
suitable neutrino masses for the large angle MSW solution are obtained without
any fine-tuning d...

It is studied that `no-scale' model makes hierarchy between scalar top mass
and Z boson mass naturally. The supersymmetry breaking parameters are
constrained by flavor changing neutral currents in minimal supersymmetric
standard model. One of the ...

The singular seesaw mechanism can naturally explain the atmospheric neutrino
deficit by the maximal oscillation between and .
This mechanism can also induce three different scales of neutrino mass squared
differences, wh...

The multi-body neutrino potential energy is analytically estimated for a
spherical neutron star with a vector potential model for neutrinos. We show
that the self-energy and the neutrino number of the neutron star coincide with
the semi-classical ...

The sliding singlet mechanism is one of the most interesting solutions of the
triplet-doublet splitting problem. We analyze this mechanism in the gauge
mediated supersymmetry breaking scenario. We show that the sliding singlet
mechanism does not w...

Effects of soft breaking in N=1 supersymmetric gauge theories are studied.
For N_f < N_c, we include the dynamics of the non-perturbative superpotential
and use the original (s)quark and gauge fields. For N_f > N_c +1, we formulate
the dynamics in...

We analyze the effects of soft supersymmetry breaking terms on N=1
supersymmetric QCD with flavors and color gauge group . The mass
squared of some squarks may be negative, as long as vacuum stability is ensured
by a simple mass ine...