1,393 research outputs found
One-Loop Renormalization of Lee-Wick Gauge Theory
We examine the renormalization of Lee-Wick gauge theory to one loop order. We
show that only knowledge of the wavefunction renormalization is necessary to
determine the running couplings, anomalous dimensions, and vector boson masses.
In particular, the logarithmic running of the Lee-Wick vector boson mass is
exactly related to the running of the coupling. In the case of an
asymptotically free theory, the vector boson mass runs to infinity in the
ultraviolet. Thus, the UV fixed point of the pure gauge theory is an ordinary
quantum field theory. We find that the coupling runs more quickly in Lee-Wick
gauge theory than in ordinary gauge theory, so the Lee-Wick standard model does
not naturally unify at any scale. Finally, we present results on the beta
function of more general theories containing dimension six operators which
differ from previous results in the literature.Comment: 17 pages, 7 figure
Spinor Helicity and Dual Conformal Symmetry in Ten Dimensions
The spinor helicity formalism in four dimensions has become a very useful
tool both for understanding the structure of amplitudes and also for practical
numerical computation of amplitudes. Recently, there has been some discussion
of an extension of this formalism to higher dimensions. We describe a
particular implementation of the spinor-helicity method in ten dimensions.
Using this tool, we study the tree-level S-matrix of ten dimensional super
Yang-Mills theory, and prove that the theory enjoys a dual conformal symmetry.
Implications for four-dimensional computations are discussed.Comment: 24 pages, 1 figure
Extended Superscaling of Electron Scattering from Nuclei
An extended study of scaling of the first and second kinds for inclusive
electron scattering from nuclei is presented. Emphasis is placed on the
transverse response in the kinematic region lying above the quasielastic peak.
In particular, for the region in which electroproduction of resonances is
expected to be important, approximate scaling of the second kind is observed
and the modest breaking of it is shown probably to be due to the role played by
an inelastic version of the usual scaling variable.Comment: LaTeX, 36 pages including 5 color postscript figures and 4 postscript
figure
The Kinematic Algebra From the Self-Dual Sector
We identify a diffeomorphism Lie algebra in the self-dual sector of
Yang-Mills theory, and show that it determines the kinematic numerators of
tree-level MHV amplitudes in the full theory. These amplitudes can be computed
off-shell from Feynman diagrams with only cubic vertices, which are dressed
with the structure constants of both the Yang-Mills colour algebra and the
diffeomorphism algebra. Therefore, the latter algebra is the dual of the colour
algebra, in the sense suggested by the work of Bern, Carrasco and Johansson. We
further study perturbative gravity, both in the self-dual and in the MHV
sectors, finding that the kinematic numerators of the theory are the BCJ
squares of the Yang-Mills numerators.Comment: 29 pages, 5 figures. v2: references added, published versio
Exciton-plasmon states in nanoscale materials: breakdown of the Tamm-Dancoff approximation
Within the Tamm-Dancoff approximation ab initio approaches describe excitons
as packets of electron-hole pairs propagating only forward in time. However, we
show that in nanoscale materials excitons and plasmons hybridize, creating
exciton--plasmon states where the electron-hole pairs oscillate back and forth
in time. Then, as exemplified by the trans-azobenzene molecule and carbon
nanotubes, the Tamm-Dancoff approximation yields errors as large as the
accuracy claimed in ab initio calculations. Instead, we propose a general and
efficient approach that avoids the Tamm--Dancoff approximation, and correctly
describes excitons, plasmons and exciton-plasmon states
Off-shell effects in dilepton production from hot interacting mesons
The production of dielectrons in reactions involving a_1 mesons and pions is
studied. We compare results obtained with different phenomenological
Lagrangians that have been used in connection with hadronic matter and finite
nuclei. We insist on the necessity for those interactions to satisfy known
empirical properties of the strong interaction. Large off-shell effects in
dielectron production are found and some consequences for the interpretation of
heavy ion data are outlined. We also compare with results obtained using
experimentally-extracted spectral functions.Comment: 14 pages, LaTeX2e, 2 figure
PEG Branched Polymer for Functionalization of Nanomaterials with Ultralong Blood Circulation
Nanomaterials have been actively pursued for biological and medical
applications in recent years. Here, we report the synthesis of several new
poly(ethylene glycol) grafted branched-polymers for functionalization of
various nanomaterials including carbon nanotubes, gold nanoparticles (NP) and
gold nanorods (NRs), affording high aqueous solubility and stability for these
materials. We synthesize different surfactant polymers based upon
poly-(g-glutamic acid) (gPGA) and poly(maleic anhydride-alt-1-octadecene)
(PMHC18). We use the abundant free carboxylic acid groups of gPGA for attaching
lipophilic species such as pyrene or phospholipid, which bind to nanomaterials
via robust physisorption. Additionally, the remaining carboxylic acids on gPGA
or the amine-reactive anhydrides of PMHC18 are then PEGylated, providing
extended hydrophilic groups, affording polymeric amphiphiles. We show that
single-walled carbon nanotubes (SWNTs), Au NPs and NRs functionalized by the
polymers exhibit high stability in aqueous solutions at different pHs, at
elevated temperatures and in serum. Morever, the polymer-coated SWNTs exhibit
remarkably long blood circulation (t1/2 22.1 h) upon intravenous injection into
mice, far exceeding the previous record of 5.4 h. The ultra-long blood
circulation time suggests greatly delayed clearance of nanomaterials by the
reticuloendothelial system (RES) of mice, a highly desired property for in vivo
applications of nanomaterials, including imaging and drug delivery
Production of intermediate-mass dileptons in relativistic heavy ion collisions
The production of intermediate mass dileptons in ultrarelativistic nuclear
collisions at SPS energies is studied. The acceptance and detector resolution
inherent to measurements by the NA50 experimental collaboration are accurately
modeled. The measured centrality dependence of the intermediate mass lepton
pair excess is also addressed.Comment: 9 pages, 8 figures, ReVTe
Current Practices in Global/International Advanced Pharmacy Practice Experiences: Home/Host Country or Site/Institution Considerations
International outreach by schools and colleges of pharmacy is increasing. In this paper, we provide current practice guidelines to establish and maintain successful global/international advanced pharmacy practice experiences (G/I APPEs) with specific recommendations for home/host country and host site/institution. The paper is based on a literature review (2000-2014) in databases and Internet searches with specific keywords or terms. Educational documents such as syllabi and memoranda of understanding (MoUs) from pharmacy programs were also examined. In addition, a preliminary draft was developed and the findings and recommendations were reviewed in a 90-minute roundtable discussion at the 2014 American Association of Colleges of Pharmacy Annual Meeting. Recommendations for the host country include travel considerations (eg, passport, visa, air travel), safety, housing, transportation, travel alerts and warnings, health issues, and financial considerations. For the home country, considerations for establishment of G/I APPE site (eg, vetting process, MoU, site expectations) are described. The paper is a resource for development of new G/I APPEs and provides guidance for continuous quality improvement of partnerships focusing on G/I pharmacy education
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