γ−\gamma-ray line generated by the Green-Schwarz mechanism

We study the phenomenology of a $U_X(1)$ 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 $X$, 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 $\hbar$-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 BB Meson Decays Into A Highly Excited Charmed Meson Doublet

We study the heavy quark effective theory prediction for semileptonic $B$ decays into an orbital excited $F$-wave charmed doublet, the ($2^{+}$, $3^{+}$) states ($D^{*'}_{2}$, $D_{3}$), 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 $\Gamma_{B\to D^{*'}_{2}\ell\overline{\nu}}=1.85\times10^{-19} {GeV}$ and $\Gamma_{B\to D_{3}\ell\overline{\nu}}=1.78\times10^{-19} {GeV}$. The branching ratios are $\mathcal {B}(B\to D_{2}^{*'}\ell\overline{\nu})=4.6\times10^{-7}$ and $\mathcal {B}(B\to D_{3}\ell\overline{\nu})=4.4\times10^{-7}$, respectively.Comment: 6 pages,2 figure