1,054 research outputs found
Spectrum of TeV Particles in Warped Supersymmetric Grand Unification
In warped supersymmetric grand unification, XY gauge particles appear near
the TeV scale along with Kaluza-Klein towers of the standard model gauge
fields. In spite of this exotic low-energy physics, MSSM gauge coupling
unification is preserved and proton decay is naturally suppressed. In this
paper we study in detail the low-lying mass spectrum of superparticles and GUT
particles in this theory, taking supersymmetry breaking to be localized to the
TeV brane. The masses of the MSSM particles, Kaluza-Klein modes, and XY states
are all determined by two parameters, one which fixes the strength of the
supersymmetry breaking and the other which sets the scale of the infrared
brane. A particularly interesting result is that for relatively strong
supersymmetry breaking, the XY gauginos and the lowest Kaluza-Klein excitations
of the MSSM gauginos may both lie within reach of the LHC, providing the
possibility that the underlying unified gauge symmetry and the enhanced N=2
supersymmetry of the theory will both be revealed.Comment: 29 pages, 5 figure
Supersymmetry Breaking and Moduli Stabilization with Anomalous U(1) Gauge Symmetry
We examine the effects of anomalous U(1)_A gauge symmetry on soft
supersymmetry breaking terms while incorporating the stabilization of the
modulus-axion multiplet responsible for the Green-Schwarz (GS) anomaly
cancellation mechanism. In case of the KKLT stabilization of the GS modulus,
soft terms are determined by the GS modulus mediation, the anomaly mediation
and the U(1)_A mediation which are generically comparable to each other,
thereby yielding the mirage mediation pattern of superparticle masses at low
energy scale. Independently of the mechanism of moduli stabilization and
supersymmetry breaking, the U(1)_A D-term potential can not be an uplifting
potential for de Sitter vacuum when the gravitino mass is smaller than the
Planck scale by many orders of magnitude. We also discuss some features of the
supersymmetry breaking by red-shifted anti-brane which is a key element of the
KKLT moduli stabilization.Comment: 32 pages; references are adde
Gauge coupling renormalization in orbifold field theories
We investigate the gauge coupling renormalization in orbifold field theories
preserving 4-dimensional N=1 supersymmetry in the framework of 4-dimensional
effective supergravity. As a concrete example, we consider the 5-dimensional
Super-Yang-Mills theory on a slice of AdS_5. In our approach, one-loop gauge
couplings can be determined by the loop-induced axion couplings and the tree
level properties of 4-dimensional effective supergravity which are much easier
to be computed.Comment: 18 pages, JHEP style; 1-loop corrections to gauge kinetic functions
are fully computed, references are adde
Effective Field Theory and Unification in AdS Backgrounds
This work is an extension of our previous work, hep-th/0204160, which showed
how to systematically calculate the high energy evolution of gauge couplings in
compact AdS_5 backgrounds. We first directly compute the one-loop effects of
massive charged scalar fields on the low energy couplings of a gauge theory
propagating in the AdS background. It is found that scalar bulk mass scales
(which generically are of order the Planck scale) enter only logarithmically in
the corrections to the tree-level gauge couplings. As we pointed out
previously, we show that the large logarithms that appear in the AdS one-loop
calculation can be obtained within the confines of an effective field theory,
by running the Planck brane correlator from a high UV matching scale down to
the TeV scale. This result exactly reproduces our previous calculation, which
was based on AdS/CFT duality. We also calculate the effects of scalar fields
satisfying non-trivial boundary conditions (relevant for orbifold breaking of
bulk symmetries) on the running of gauge couplings.Comment: LaTeX, 27 pages; minor typos fixed, comments adde
Reviewing the genetics of heterogeneity in depression: operationalizations, manifestations and etiologies
Stress and Psychopatholog
Vortex Lattice Structures of a Bose-Einstein Condensate in a Rotating Lattice Potential
We study vortex lattice structures of a trapped Bose-Einstein condensate in a
rotating lattice potential by numerically solving the time-dependent
Gross-Pitaevskii equation. By rotating the lattice potential, we observe the
transition from the Abrikosov vortex lattice to the pinned lattice. We
investigate the transition of the vortex lattice structure by changing
conditions such as angular velocity, intensity, and lattice constant of the
rotating lattice potential.Comment: 6 pages, 8 figures, submitted to Quantum Fluids and Solids Conference
(QFS 2006
Dynamical symmetry breaking in Gauge-Higgs unification of 5D SUSY theory
We study the dynamical symmetry breaking in the gauge-Higgs unification of
the 5D SUSY theory, compactified on an orbifold, .
This theory identifies Wilson line degrees of freedoms as ``Higgs doublets''.
We consider and SU(6) models, in which the gauge
symmetries are reduced to and , respectively, through the
orbifolding boundary conditions. Quarks and leptons are bulk fields, so that
Yukawa interactions can be derived from the 5D gauge interactions. We estimate
the one loop effective potential of ``Higgs doublets'', and analyze the vacuum
structures in these two models. We find that the effects of bulk quarks and
leptons destabilize the suitable electro-weak vacuum. We show that the
introduction of suitable numbers of extra bulk fields possessing the suitable
representations can realize the appropriate electro-weak symmetry breaking.Comment: 15 pages, 4 figures;disscutions on Higgs quartic couplings adde
Systematics of Coupling Flows in AdS Backgrounds
We give an effective field theory derivation, based on the running of Planck
brane gauge correlators, of the large logarithms that arise in the predictions
for low energy gauge couplings in compactified AdS}_5 backgrounds, including
the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast
to the case of charged scalars coupled to Abelian gauge fields that has been
considered previously in the literature, the one-loop corrections are not
dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge
field loops, the amplitudes can be reorganized into a leading logarithmic
contribution that is identical to the running in 4D non-Abelian gauge theory,
and a term which is not logarithmically enhanced and is analogous to a two-loop
effect in 4D. In a warped GUT model broken by the Higgs mechanism in the
bulk,we show that the matching scale that appears in the large logarithms
induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk
mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV
scale in the logarithmic contributions of scalars, which is simply the bulk
mass m. Our results are summarized in a set of simple rules that can be applied
to compute the leading logarithmic predictions for coupling constant relations
within a given warped GUT model. We present results for both bulk Higgs and
boundary breaking of the GUT gauge group.Comment: 22 pages, LaTeX, 3 figures. Comments and references adde
Theory of nonlinear Landau-Zener tunneling
A nonlinear Landau-Zener model was proposed recently to describe, among a
number of applications, the nonadiabatic transition of a Bose-Einstein
condensate between Bloch bands. Numerical analysis revealed a striking
phenomenon that tunneling occurs even in the adiabatic limit as the nonlinear
parameter is above a critical value equal to the gap of avoided
crossing of the two levels. In this paper, we present analytical results that
give quantitative account of the breakdown of adiabaticity by mapping this
quantum nonlinear model into a classical Josephson Hamiltonian. In the critical
region, we find a power-law scaling of the nonadiabatic transition probability
as a function of and , the crossing rate of the energy levels.
In the subcritical regime, the transition probability still follows an
exponential law but with the exponent changed by the nonlinear effect. For
, we find a near unit probability for the transition between the
adiabatic levels for all values of the crossing rate.Comment: 9 figure
Precision Electroweak Data and Unification of Couplings in Warped Extra Dimensions
Warped extra dimensions allow a novel way of solving the hierarchy problem,
with all fundamental mass parameters of the theory naturally of the order of
the Planck scale. The observable value of the Higgs vacuum expectation value is
red-shifted, due to the localization of the Higgs field in the extra dimension.
It has been recently observed that, when the gauge fields propagate in the
bulk, unification of the gauge couplings may be achieved. Moreover, the
propagation of fermions in the bulk allows for a simple solution to potentially
dangerous proton decay problems. However, bulk gauge fields and fermions pose a
phenomenological challenge, since they tend to induce large corrections to the
precision electroweak observables. In this article, we study in detail the
effect of gauge and fermion fields propagating in the bulk in the presence of
gauge brane kinetic terms compatible with gauge coupling unification, and we
present ways of obtaining a consistent description of experimental data, while
allowing values of the first Kaluza Klein mode masses of the order of a few
TeV.Comment: 32 pages, 7 figures. References adde
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