431,226 research outputs found
Dual versions of N=2 supergravity and spontaneous supersymmetry breaking
In this paper, using a model of N=2 supergravity - vector multiplets
interaction with the scalar field geometry as an
example, we show that even when the geometry is fixed one can have a whole
family of the Lagrangians that differ by the vector field duality
transformations. As a byproduct, for this geometry we have constructed a model
of (m-1) vector multiplets interacting with the hidden sector admitting
spontaneous supersymmetry breaking with two arbitrary scales and without a
cosmological term.Comment: 10 pages, LaTeX, IHEP preprint 94-9
Experimental observation of the longitudinal plasma excitation in intrinsic Josephson junctions
We have investigated the current-voltage characteristics (IVCs) of intrinsic
Josephson junctions (IJJs). Recently, it is predicted that the longitudinal
plasma wave can be excited by the parametric resonance in IJJs. Such an
excitation induces a singularity called as breakpoint region around switch back
region in the IVC. We have succeeded in the observation of the breakpoint
region in the IVC of the mesa with 5 IJJs at 4.2 K. Furthermore, it is found
that the temperature dependence of the breakpoint current is in agreement with
the theoretical prediction. This suggests that the wave number of the excited
plasma wave varies with temperature.Comment: 7 pages, 7 figures. Dubna-Nano2008, Accepted for JPCS
Photon spectra and anisotropic flow in heavy ion collisions at the top RHIC energy within the integrated hydrokinetic model with photon hadronization emission
The integrated HydroKinetic Model (iHKM) is applied to analyse the results of
direct photon spectra as well as elliptic and triangular flow measurements in
200A GeV Au+Au collisions at RHIC for different centrality bins. Experiments
detect the strong centrality dependence of photon elliptic and triangular flow
as increasing -coefficients towards peripheral collisions. The photon
production in the model is accumulated from the different sources along with
the process of relativistic heavy ion collision developing. Those include the
primary hard photons from the parton collisions at the very early stage of the
process, the photons generated at the pre-thermal phase of dense matter
evolution, then thermal photons at partially equilibrated hydrodynamic
quark-gluon stage, together with radiation displaying a confinement and,
finally, from the hadron gas phase. Along the way a hadronic medium evolution
is treated in two distinct, in a sense opposite, approaches: chemically
equilibrium and chemically non-equilibrium, namely, chemically frozen
expansion. We find the description of direct photon spectra, elliptic and
triangular flow are significantly improved, similar to that found in iHKM for
the LHC energies, if an additional portion of photon radiation associated with
the confinement processes, the "hadronization photons", is included into
consideration.Comment: 28 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1812.0276
Inverse problem in Parker's dynamo
The inverse solution of the 1D Parker dynamo equations is considered. The
method is based on minimization of the cost-function, which characterize
deviation of the model solution properties from the desired ones. The output is
the latitude distribution of the magnetic field generation sources: the
- and -effects. Minimization is made using the Monte-Carlo
method. The details of the method, as well as some applications, which can be
interesting for the broad dynamo community, are considered: conditions when the
invisible for the observer at the surface of the planet toroidal part of the
magnetic field is much larger than the poloidal counterpart. It is shown that
at some particular distributions of and the well-known thesis
that sign of the dynamo-number defines equatorial symmetry of the magnetic
field to the equator plane, is violated. It is also demonstrated in what
circumstances magnetic field in the both hemispheres have different properties,
and simple physical explanation of this phenomenon is proposed
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