10,221 research outputs found
ray line generated by the Green-Schwarz mechanism
We study the phenomenology of a extension of the Standard Model
where the SM particles are not charged under the new abelian group. The
Green-Schwarz mechanism insures that the model is anomaly free. The erstwhile
invisible dark gauge field , even if produced with difficulty at the LHC has
however a clear signature in gamma-ray telescopes. We investigate what BSM
scale (which can be interpreted as a low-energy string scale) would be
reachable by the FERMI/GLAST telescope after
5 years of running and show that a 1 TeV scale can be testable, which is
highly competitive with the LHC.Comment: Proceedings of DSU09 "The Dark Side of the Universe", 1-5 June 2009,
Melbourne, 6 pages, 2 figure
Global regularity for a family of 3D models of the axisymmetric Navier-Stokes equations
We consider a family of 3D models for the axi-symmetric incompressible
Navier-Stokes equations. The models are derived by changing the strength of the
convection terms in the axisymmetric Navier-Stokes equations written using a
set of transformed variables. We prove the global regularity of the family of
models in the case that the strength of convection is slightly stronger than
that of the original Navier-Stokes equations, which demonstrates the potential
stabilizing effect of convection
Generalized Second-Order Thomas-Fermi Method for Superfluid Fermi Systems
Using the -expansion of the Green's function of the
Hartree-Fock-Bogoliubov equation, we extend the second-order Thomas-Fermi
approximation to generalized superfluid Fermi systems by including the
density-dependent effective mass and the spin-orbit potential. We first
implement and examine the full correction terms over different energy intervals
of the quasiparticle spectra in calculations of finite nuclei. Final
applications of this generalized Thomas-Fermi method are intended for various
inhomogeneous superfluid Fermi systems.Comment: 8 pages, 10 figures, PR
The institutional change in China after its reform in 1979; an institutional analysis with a focus on mergers and acquisitions
Het onderzoek richt zich op de analyse van het proces van institutionele verandering in China, zoals zich dat heeft voltrokken vanaf 1949 tot 2004. De aandacht gaat vooral uit naar de periode na 1979 toen de Chinese overheid de weg in sloeg naar een meer marktgeoriënteerde economie. Wat de institutionele veranderingen betreft is de analyse vooral gericht op de herstructurering van de staatsondernemingen en de rol van fusies en overnamen (F&O) in dat proces.
In hoofdstuk 1 worden de onderzoeksvraag geformuleerd, het theoretische kader gepresenteerd en de methodologie besproken.
De onderzoeksvraag luidt als volgt: welke institutionele veranderingen vonden na 1979 plaats in het economische systeem van China, hoe kan het proces van institutionele verandering worden gekarakteriseerd en wat waren de gevolgen voor het Chinese economische systeem? Vier subvragen worden gespecificeerd:
- Hoe functioneerde het economische systeem voor 1979 (de centraal geleide economie)?
- Hoe kan het proces van verandering worden gekarakteriseerd in termen van incrementele of radicale veranderingen?
- Hoe kan het huidige systeem worden gekarakteriseerd; is sprake van een overgangssituatie, is sprake van inconsistenties?
- Hoe zullen de processen van institutionele verandering de toekomst van het Chinese economische systeem beïnvloeden
Gold Nanostructures for Sensing and Functional Bioimaging
Gold nanostructures offer an extremely promising path forward in the fields of imaging and sensing because of their unique optical and chemical properties. Here, we demonstrate that plasmonic nanostructures can be employed as nanoscale transducers to monitor the growth and phase transitions in ultrathin polymer films. In particular, gold nanorods with high refractive index sensitivity (~150 nm / refractive index unit (RIU)) were employed to probe the growth and swelling of polyelectrolyte multilayers (PEM). By comparing the wavelength shift and extinction intensity of the localized surface plasmon resonance (LSPR) of the gold nanorods coated with PEM in air and water, the swelling of PEM was estimated to be 26%±6%, which was confirmed with AFM imaging in air and water. The deployment of shape-controlled metal nanostructures with high refractive index sensitivity represents a novel and facile approach for monitoring the phase transition in polymers with nanoscale resolution.
Additionally, we demonstrate bio-enabled synthesis of a novel class of functional SERS probes with built-in and accessible electromagnetic hotspots, which are formed by densely packed satellites grown on a gold plasmonic core. These accessible electromagnetic hotspots enable facile sampling of the surrounding complex biological milieu. The core-satellite superstructures serve as nanoscale sensors to spatiotemporally map intravesicular pH changes along endocytic pathways inside a living cell. Furthermore, we show that through rational choice of core shape, photothermal efficiency of the nanostructures can be modulated to realize either of the following: imaging probes with minimal heating, or multifunctional theranostic agents that can image and photothermally kill the cells for locoregional therapy. Bright, stable and multifunctional exogenous contrast agents are critical for advancing surface enhanced Raman scattering (SERS)-based functional bioimaging and image-guided therapy
Boson Core Compressibility
Strongly interacting atoms trapped in optical lattices can be used to explore
phase diagrams of Hubbard models. Spatial inhomogeneity due to trapping
typically obscures distinguishing observables. We propose that measures using
boson double occupancy avoid trapping effects to reveal key correlation
functions. We define a boson core compressibility and core superfluid stiffness
in terms of double occupancy. We use quantum Monte Carlo on the Bose-Hubbard
model to empirically show that these quantities intrinsically eliminate edge
effects to reveal correlations near the trap center. The boson core
compressibility offers a generally applicable tool that can be used to
experimentally map out phase transitions between compressible and
incompressible states.Comment: 11 pages, 11 figure
Semileptonic Meson Decays Into A Highly Excited Charmed Meson Doublet
We study the heavy quark effective theory prediction for semileptonic
decays into an orbital excited -wave charmed doublet, the (, )
states (, ), at the leading order of heavy quark expansion.
The corresponding universal form factor is estimated by using the QCD sum rule
method. The decay rates we predict are and . The branching ratios are
and
, respectively.Comment: 6 pages,2 figure
- …