117,206 research outputs found
T-Parity Violation by Anomalies
Little Higgs theories often rely on an internal parity ("T-parity'') to
suppress non-standard electroweak effects or to provide a dark matter
candidate. We show that such a symmetry is generally broken by anomalies, as
described by the Wess-Zumino-Witten term. We study a simple SU(3) x SU(3)/SU(3)
Little Higgs scheme where we obtain a minimal form for the topological
interactions of a single Higgs field. The results apply to more general models,
including [SU(3) x SU(3)/SU(3)]^4, SU(5)/SO(5), and SU(6)/Sp(6).Comment: 17 page
Prototype Environmental Assessment of the impacts of siting and construction of an SPS ground receiving station
A prototype assessment of the environmental impacts of siting and constructing a Satellite Power System (SPS) Ground Receiving Station (GRS) is reported. The objectives of the study were: (1) to develop an assessment of the nonmicrowave related impacts of the reference system SPS GRS on the natural environment; (2) to assess the impacts of GRS construction and operations in the context of actual baseline data for a site in the California desert; and (3) to identify critical GRS characteristics or parameters that are most significant in terms of the natural environment
Topological Physics of Little Higgs Bosons
Topological interactions will generally occur in composite Higgs or Little
Higgs theories, extra-dimensional gauge theories in which A_5 plays the role of
a Higgs boson, and amongst the pNGB's of technicolor. This phenomena arises
from the chiral and anomaly structure of the underlying UV completion theory,
and/or through chiral delocalization in higher dimensions. These effects are
described by a full Wess-Zumino-Witten term involving gauge fields and pNGB's.
We give a general discussion of these interactions, some of which may have
novel signatures at future colliders, such as the LHC and ILC.Comment: 22 page
The modern description of semileptonic meson form factors
I describe recent advances in our understanding of the hadronic form factors
governing semileptonic meson transitions. The resulting framework provides a
systematic approach to the experimental data, as a means of extracting
precision observables, testing nonperturbative field-theory methods, and
probing a poorly understood limit of QCD.Comment: 13 pages, 9 figures. Invited talk presented at Flavor Physics and CP
Violation Conference, Vancouver, 2006; figure 9 updated with new experimental
data, references adde
Transport in polymer-gel composites: Theoretical methodology and response to an electric field
A theoretical model of electromigrative, diffusive and convectivetransport
polymer-gel composites is presented. Bulk properties are derived from the
standard electrokinetic model with an impenetrable charged sphere embedded in
an electrolyte-saturated Brinkman medium. Because the microstructure can be
carefully controlled, these materials are promising candidates for enhanced
gel-electrophoresis, chemical sensing, drug delivery, and microfluidic pumping
technologies. The methodology provides `exact' solutions for situations where
perturbations from equilibrium are induced by gradients of electrostatic
potential, concentration and pressure. While the volume fraction of the
inclusions should be small, Maxwell's well-known theory of conduction suggests
that the theory may also be accurate at moderate volume fractions. In this
work, the model is used to compute ion fluxes, electrical current density, and
convective flow induced by an applied electric field. The
electric-field-induced (electro-osmotic) flow is a sensitive indicator of the
inclusion zeta-potential and size, electrolyte concentration, and Darcy
permeability of the gel, while the electrical conductivity increment is most
often independent of the polymer gel, and is much less sensitive to particle
and electrolyte characteristics
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