4,565 research outputs found
Y-Scaling Analysis of the Deuteron Within the Light-Front Dynamics Method
The concept of relativistic scaling is applied to describe the most recent
data from inclusive electron-deuteron scattering at large momentum transfer. We
calculate the asymptotic scaling function f(y) of the deuteron using its
relationship with the nucleon momentum distribution. The latter is obtained in
the framework of the relativistic light-front dynamics (LFD) method, in which
the deuteron is described by six invariant functions f_{i} (i=1,...,6) instead
of two (S and D waves) in the nonrelativistic case. Comparison of the LFD
asymptotic scaling function with other calculations using and waves
corresponding to various nucleon-nucleon potentials, as well as with the
Bethe-Salpeter result is made. It is shown that for |y|> 400 MeV/c the
differences between the LFD and the nonrelativistic scaling functions become
larger.Comment: 7 pages, 5 figures, Talk at 21-st International Workshop on Nuclear
Theory, Rila Mountains, Bulgaria, June 10-15, 200
Geometrical Description of the Local Integrals of Motion of Maxwell-Bloch Equation
We represent a classical Maxwell-Bloch equation and related to it positive
part of the AKNS hierarchy in geometrical terms. The Maxwell-Bloch evolution is
given by an infinitesimal action of a nilpotent subalgebra of affine Lie
algebra on a Maxwell-Bloch phase space treated as a homogeneous
space of . A space of local integrals of motion is described using
cohomology methods. We show that hamiltonian flows associated to the
Maxwell-Bloch local integrals of motion (i.e. positive AKNS flows) are
identified with an infinitesimal action of an abelian subalgebra of the
nilpotent subalgebra on a Maxwell- Bloch phase space. Possibilities of
quantization and latticization of Maxwell-Bloch equation are discussed.Comment: 16 pages, no figures, plain TeX, no macro
Magnetization reversal process and nonlinear magneto-impedance in Cu/NiFe and Nb/NiFe composite wires
The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC
current is studied. The frequency spectrum of a voltage induced in a pick-up
coil wound around the wire is analyzed. The frequency spectrum is shown to
consist of even harmonics within a wide range of AC current amplitudes and
longitudinal DC magnetic fields. The strong dependencies of the harmonic
amplitudes on the DC field are found. The results obtained may be of importance
for the design of weak magnetic field sensors.Comment: 8 pages, 4 figures, publishe
Steady state existence of passive vector fields under the Kraichnan model
The steady state existence problem for Kraichnan advected passive vector
models is considered for isotropic and anisotropic initial values in arbitrary
dimension. The model includes the magnetohydrodynamic (MHD) equations, linear
pressure model (LPM) and linearized Navier-Stokes (LNS) equations. In addition
to reproducing the previously known results for the MHD and linear pressure
model, we obtain the values of the Kraichnan model roughness parameter
for which the LNS steady state exists.Comment: Improved text & figures, added references & other correction
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