669 research outputs found
Fabricating plasmonic components for nanophotonics:[invited]
We report on experimental realization of different metal-dielectric structures that are used as surface plasmon polariton waveguides and as plasmonic metamaterials. Fabrication approaches based on different lithographic and deposition techniques are discussed
Magnetoluminescence
Pulsar Wind Nebulae, Blazars, Gamma Ray Bursts and Magnetars all contain
regions where the electromagnetic energy density greatly exceeds the plasma
energy density. These sources exhibit dramatic flaring activity where the
electromagnetic energy distributed over large volumes, appears to be converted
efficiently into high energy particles and gamma-rays. We call this general
process magnetoluminescence. Global requirements on the underlying, extreme
particle acceleration processes are described and the likely importance of
relativistic beaming in enhancing the observed radiation from a flare is
emphasized. Recent research on fluid descriptions of unstable electromagnetic
configurations are summarized and progress on the associated kinetic
simulations that are needed to account for the acceleration and radiation is
discussed. Future observational, simulation and experimental opportunities are
briefly summarized.Comment: To appear in "Jets and Winds in Pulsar Wind Nebulae, Gamma-ray Bursts
and Blazars: Physics of Extreme Energy Release" of the Space Science Reviews
serie
Distributed phase-covariant cloning with atomic ensembles via quantum Zeno dynamics
We propose an interesting scheme for distributed orbital state quantum
cloning with atomic ensembles based on the quantum Zeno dynamics. These atomic
ensembles which consist of identical three-level atoms are trapped in distant
cavities connected by a single-mode integrated optical star coupler. These
qubits can be manipulated through appropriate modulation of the coupling
constants between atomic ensemble and classical field, and the cavity decay can
be largely suppressed as the number of atoms in the ensemble qubits increases.
The fidelity of each cloned qubit can be obtained with analytic result. The
present scheme provides a new way to construct the quantum communication
network.Comment: 5 pages, 4 figure
Enamel remineralization via poly(amido amine) and adhesive resin containing calcium phosphate nanoparticles
Objectives:The objective of this study was to investigate enamel remineralization using salivary statherin pro-tein-inspired poly(amidoamine) dendrimer (SN15-PAMAM) and adhesive containing nanoparticles of amor-phous calcium phosphate (NACP) in a cyclic artificial saliva/demineralizing solution for thefirst time.Methods:The enamel shear bond strengths of NACP adhesives were measured compared to commercial adhesive(Scotchbond Multi-Purpose, 3 M). Adhesive disks containing NACP were tested for calcium (Ca) and phosphorus(P) ions release. Four groups were tested: (1) enamel control, (2) enamel with NACP, (3) enamel with SN15-PAMAM, and (4) enamel with SN15-PAMAM + NACP. The specimens were treated with cyclic artificial saliva/demineralizing solution for 28 days. The remineralized enamel specimens were examined by surface and cross-sectional hardness test.Results:NACP adhesive yielded a similar shear bond strength to commercial control (Scotchbond Multi-Purpose,3 M). NACP adhesive released high levels of Ca and P ions. At 28 days, the enamel hardness of SN15-PAMAM +NACP group was 2.89 ± 0.13 GPa, significantly higher than that of control group (1.46 ± 0.10 GPa) (p< 0.05).SN15-PAMAM + NACP increased the enamel cross-sectional hardness at 28 days; at 25μm, enamel cross-sectional hardness was 90 % higher than that of control group (p< 0.05).Significance:The novel SN15-PAMAM + NACP adhesive method could achieve 90 % higher enamel reminer-alization of the artificial caries than the control under acid challenge for thefirst time. This method is promisingfor use after tooth cavity preparation, or as a coating on enamel with white spot lesions (WSLs) for prevention, toreduce secondary caries, prevent caries procession and protect tooth structures
Nano-structured SnO2-carbon composites obtained by in situ spray pyrolysis method as anodes in lithium batteries
Lower limit on the neutralino mass in the general MSSM
We discuss constraints on SUSY models with non-unified gaugino masses and R_P
conservation. We derive a lower bound on the neutralino mass combining the
direct limits from LEP, the indirect limits from gmuon, bsgamma, Bsmumu and the
relic density constraint from WMAP. The lightest neutralino (mneutralino=6GeV)
is found in models with a light pseudoscalar with MA<200GeV and a large value
for . Models with heavy pseudoscalars lead to mneutralino>18(29)GeV
for . We show that even a very conservative bound from the
muon anomalous magnetic moment can increase the lower bound on the neutralino
mass in models with mu<0 and/or large values of . We then examine
the potential of the Tevatron and the direct detection experiments to probe the
SUSY models with the lightest neutralinos allowed in the context of light
pseudoscalars with high . We also examine the potential of an e+e-
collider of 500GeV to produce SUSY particles in all models with neutralinos
lighter than the W. In contrast to the mSUGRA models, observation of at least
one sparticle is not always guaranteed.Comment: 37 pages, LateX, 16 figures, paper with higher resolution figures
available at
http://wwwlapp.in2p3.fr/~boudjema/papers/bound-lsp/bound-lsp.htm
Observation of the and the Y(2175) in
The cross sections for and e^+ e^- \to \phi
\fzero are measured from threshold to using
initial state radiation. The analysis is based on a data sample of 673
fb collected on and below the resonance with the Belle
detector at the KEKB asymmetric-energy collider. First measurements
are reported for the resonance parameters of the in the
mode: MeV/ and MeV/. A structure at ,
corresponding to the so called Y(2175), is observed; its mass and width are
determined to be MeV/ and , respectively.Comment: 11 pages, 6 figures. Add one plot. Accepted by Phys.Rev.D(RC
Measurement of CP asymmetry in Cabibbo suppressed D0 decays
We measure the CP-violating asymmetries in decays to the D0 -> K+K- and D0 ->
pi+pi- CP eigenstates using 540 fb^{-1} of data collected with the Belle
detector at or near the Upsilon(4S) resonance. Cabibbo-favored D0 -> K-pi+
decays are used to correct for systematic detector effects. The results,
A_{CP}^{KK} = (-0.43 +- 0.30 +- 0.11)% and A_{CP}^{pipi} = (+0.43 +- 0.52 +-
0.12)%, are consistent with no CP violation.Comment: Submitted to Phys. Lett.
Study of Decays
We report on a study of decays using
29.1 fb of annihilation data recorded at the
resonance with the Belle detector at the KEKB storage ring. Making no
assumptions about the intermediate mechanism, the branching fractions for
and are
determined to be and respectively. An analysis of candidates yields to the first observation of the color-suppressed
hadronic decay with the branching fraction . We measure the ratio of branching fractions
= 1.6 0.8.Comment: 13 pages, LaTex, 4 figures, submitted to Phys. Lett.
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