1,551 research outputs found

### Unitary Structure of the QCD Sum Rules and KYN and KY\Xi Couplings

New relations between QCD Borel sum rules for strong coupling constants of
K-mesons to baryons are derived. It is shown that starting from the sum rule
for the coupling constants $g_{\pi\Sigma\Sigma}$ and $g_{\pi\Sigma\Lambda}$ it
is straightforward to obtain corresponding sum rules for the $g_{K Y N}$, $g_{K
Y \Xi}$ couplings, $Y=\Sigma,\Lambda$.Comment: 7 pages, 2 tables, International Workshop on Quantum
Chromodynamics:Theory and Experiment, QCD@Work-2005, Coversano(Bari, Italy),
16-20 June, 200

### Reducing Interconnect Cost in NoC through Serialized Asynchronous Links

This work investigates the application of serialization as a means of reducing the number of wires in NoC combined with asynchronous links in order to simplify the clocking of the link. Throughput is reduced but savings in routing area and reduction in power could make this attractiv

### Faddeev approach to confined three-quark problems

We propose a method that allows for the efficient solution of the three-body
Faddeev equations in the presence of infinitely rising confinement
interactions. Such a method is useful in calculations of nonrelativistic and
especially semirelativistic constituent quark models. The convergence of the
partial wave series is accelerated and possible spurious contributions in the
Faddeev components are avoided. We demonstrate how the method works with the
example of the Goldstone-boson-exchange chiral quark model for baryons.Comment: 6 page

### Effects of Spatial Dispersion on Reflection from Mushroom-type Artificial Impedance Surfaces

Several recent works have emphasized the role of spatial dispersion in wire
media, and demonstrated that arrays of parallel metallic wires may behave very
differently from a uniaxial local material with negative permittivity. Here, we
investigate using local and non-local homogenization methods the effect of
spatial dispersion on reflection from the mushroom structure introduced by
Sievenpiper. The objective of the paper is to clarify the role of spatial
dispersion in the mushroom structure and demonstrate that under some conditions
it is suppressed. The metamaterial substrate, or metasurface, is modeled as a
wire medium covered with an impedance surface. Surprisingly, it is found that
in such configuration the effects of spatial dispersion may be nearly
suppressed when the slab is electrically thin, and that the wire medium can be
modeled very accurately using a local model. This result paves the way for the
design of artificial surfaces that exploit the plasmonic-type response of the
wire medium slab.Comment: submitted for publication, under revie

### Three charged particles in the continuum. Astrophysical examples

We suggest a new adiabatic approach for description of three charged
particles in the continuum. This approach is based on the Coulomb-Fourier
transformation (CFT) of three body Hamiltonian, which allows to develop a
scheme, alternative to Born-Oppenheimer one.
The approach appears as an expansion of the kernels of corresponding integral
transformations in terms of small mass-ratio parameter. To be specific, the
results are presented for the system $ppe$ in the continuum. The wave function
of a such system is compared with that one which is used for estimation of the
rate for triple reaction $p+p+e\to d+\nu,$ which take place as a step of
$pp$-cycle in the center of the Sun. The problem of microscopic screening for
this particular reaction is discussed

### Electron-muon heat conduction in neutron star cores via the exchange of transverse plasmons

We calculate the thermal conductivity of electrons and muons kappa_{e-mu}
produced owing to electromagnetic interactions of charged particles in neutron
star cores and show that these interactions are dominated by the exchange of
transverse plasmons (via the Landau damping of these plasmons in
nonsuperconducting matter and via a specific plasma screening in the presence
of proton superconductivity). For normal protons, the Landau damping strongly
reduces kappa_{e-mu} and makes it temperature independent. Proton
superconductivity suppresses the reduction and restores the Fermi-liquid
behavior kappa_{e-mu} ~ 1/T. Comparing with the thermal conductivity of
neutrons kappa_n, we obtain kappa_{e-mu}> kappa_n for T>2 GK in normal matter
and for any T in superconducting matter with proton critical temperatures
T_c>3e9 K. The results are described by simple analytic formulae.Comment: 15 pages, 5 figures, to appear in Phys. Rev.

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