1,521 research outputs found
Domain Bubbles of Extra Dimensions
``Dimension bubbles'' of the type previously studied by Blau and Guendelman
[S.K. Blau and E.I. Guendelman, Phys. Rev. D40, 1909 (1989)], which effectively
enclose a region of 5d spacetime and are surrounded by a region of 4d
spacetime, can arise in a 5d theory with a compact extra dimension that is
dimensionally reduced to give an effective 4d theory. These bubbles with thin
domain walls can be stabilized against total collapse in a rather natural way
by a scalar field which, as in the case with ``ordinary'' nontopological
solitons, traps light scalar particles inside the bubble.Comment: 13 pages, no figures; to appear in Phys.Rev.
Mesoscopic Fluctuations in Quantum Dots in the Kondo Regime
Properties of the Kondo effect in quantum dots depend sensitively on the
coupling parameters and so on the realization of the quantum dot -- the Kondo
temperature itself becomes a mesoscopic quantity. Assuming chaotic dynamics in
the dot, we use random matrix theory to calculate the distribution of both the
Kondo temperature and the conductance in the Coulomb blockade regime. We study
two experimentally relevant cases: leads with single channels and leads with
many channels. In the single-channel case, the distribution of the conductance
is very wide as fluctuates on a logarithmic scale. As the number of
channels increases, there is a slow crossover to a self-averaging regime.Comment: 4 pages, 3 figure
Family Unification with SO(10)
Unification based on the group SO(10)^3 \times S_3 is studied. Each family
has its own SO(10) group, and the S_3 permutes the three families and SO(10)
factors. This is the maximal local symmetry for the known fermions. Family
unification is achieved in the sense that all known fermions are in a single
irreducible multiplet of the symmetry. The symmetry suppresses SUSY flavor
changing effects by making all squarks and sleptons degenerate in the symmetry
limit. Doublet-triplet splitting can arise simply, and non-trivial structure of
the quark and lepton masses emerges from the gauge symmetry, including the
"doubly lopsided" form.Comment: 11 pages, references adde
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Internal fluid flow management analysis for Clinch River Breeder Reactor Plant sodium pumps
The Clinch River Breeder Reactor Plant (CRBRP) sodium pumps are currently being designed and the prototype unit is being fabricated. In the design of these large-scale pumps for elevated temperature Liquid Metal Fast Breeder Reactor (LMFBR) service, one major design consideration is the response of the critical parts to severe thermal transients. A detailed internal fluid flow distribution analysis has been performed using a computer code HAFMAT, which solves a network of fluid flow paths. The results of the analytical approach are then compared to the test data obtained on a half-scale pump model which was tested in water. The details are presented of pump internal hydraulic analysis, and test and evaluation of the half-scale model test results
Blockchain-Based Transaction Validation Protocol for a Secure Distributed IoT Network
Funding Agency: 10.13039/501100010418-Institute for Information and Communications Technology Promotion (IITP), Ministry of Science and ICT (MSIT); 10.13039/501100003621-Korea Government;Peer reviewedPublisher PD
Time-reversal violating rotation of polarization plane of light in gas placed in electric field
Rotation of polarization plane of light in gas placed in electric field is
considered. Different factors causing this phenomenon are investigated. Angle
of polarization plane rotation for transition 6S_{1/2} - 7S_{1/2} in cesium
(lambda=539 nm) is estimated. The possibility to observe this effect
experimentally is discussed.Comment: 10 pages, Late
Anti-Kondo resonance in transport through a quantum wire with a side-coupled quantum dot
An interacting quantum dot side-coupled to a perfect quantum wire is studied.
Transport through the quantum wire is investigated by using an exact sum rule
and the slave-boson mean field treatment. It is shown that the Kondo effect
provides a suppression of the transmission due to the destructive interference
of the ballistic channel and the Kondo channel. At finite temperatures,
anti-resonance behavior is found as a function of the quantum dot level
position, which is interpreted as a crossover from the high temperature Kondo
phase to the low temperature charge fluctuation phase.Comment: 4 pages Revtex, 3 eps figure
From Fractional Chern Insulators to a Fractional Quantum Spin Hall Effect
We investigate the algebraic structure of flat energy bands a partial filling
of which may give rise to a fractional quantum anomalous Hall effect (or a
fractional Chern insulator) and a fractional quantum spin Hall effect. Both
effects arise in the case of a sufficiently flat energy band as well as a
roughly flat and homogeneous Berry curvature, such that the global Chern
number, which is a topological invariant, may be associated with a local
non-commutative geometry. This geometry is similar to the more familiar
situation of the fractional quantum Hall effect in two-dimensional electron
systems in a strong magnetic field.Comment: 8 pages, 3 figure; published version with labels in Figs. 2 and 3
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Twisted Vortices in a Gauge Field Theory
We inspect a particular gauge field theory model that describes the
properties of a variety of physical systems, including a charge neutral
two-component plasma, a Gross-Pitaevskii functional of two charged Cooper pair
condensates, and a limiting case of the bosonic sector in the Salam-Weinberg
model. It has been argued that this field theory model also admits stable
knot-like solitons. Here we produce numerical evidence in support for the
existence of these solitons, by considering stable axis-symmetric solutions
that can be thought of as straight twisted vortex lines clamped at the two
ends. We compute the energy of these solutions as a function of the amount of
twist per unit length. The result can be described in terms of a energy
spectral function. We find that this spectral function acquires a minimum which
corresponds to a nontrivial twist per unit length, strongly suggesting that the
model indeed supports stable toroidal solitons.Comment: 10 pages, 5 figures, title changed, minor revisions, and more
references adde
Supersymmetric CP Violation in in Minimal Supergravity Model
Direct CP asymmetries and the CP violating normal polarization of lepton in
inclusive decay B \to X_s l^+ l^- are investigated in minimal supergravity
model with CP violating phases. The contributions coming from exchanging
neutral Higgs bosons are included. It is shown that the direct CP violation in
branching ratio, A_{CP}^1, is of {\cal{O}}(10^{-3}) for l=e, \mu, \tau. The CP
violating normal polarization for l=\mu can reach 0.5 percent when tan\beta is
large (say, 36). For l=\tau and in the case of large \tan\beta, the direct CP
violation in backward-forward asymmetry, A_{CP}^2, can reach one percent, the
normal polarization of \tau can be as large as a few percent, and both are
sensitive to the two CP violating phases, \phi_\mu and \phi_{A_0}, and
consequently it could be possible to observe them (in particular, the normal
polarization of \tau) in the future B factories.Comment: 14 pages, latex, 5 figure
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