5,620 research outputs found
Resistojet systems studies directed to the space station/space base. Volume 2 - Biowaste resistojet system development program Final report
Space station/base biowaste resistojet system for orbit keeping and control moment gyro desaturation - systems developmen
Isospin emission and flows at high baryon density: a test of the symmetry potential
High energy Heavy Ion Collisions (HIC) are studied in order to access nuclear
matter properties at high density. Particular attention is paid to the
selection of observables sensitive to the poorly known symmetry energy at high
baryon density, of large fundamental interest, even for the astrophysics
implications. Using fully consistent transport simulations built on effective
theories we test isospin observables ranging from nucleon/cluster emissions to
collective flows (in particular the elliptic, squeeze out, part). The effects
of the competition between stiffness and momentum dependence of the Symmetry
Potential on the reaction dynamics are thoroughly analyzed. In this way we try
to shed light on the controversial neutron/proton effective mass splitting at
high baryon and isospin densities. New, more exclusive, experiments are
suggested.Comment: 10 pages, 16 figures, new figure added, accepted for publication in
Phys.Rev.
Isospin emission and flows at high baryon density: a test of the symmetry potential
High energy Heavy Ion Collisions (HIC) are studied in order to access nuclear
matter properties at high density. Particular attention is paid to the
selection of observables sensitive to the poorly known symmetry energy at high
baryon density, of large fundamental interest, even for the astrophysics
implications. Using fully consistent transport simulations built on effective
theories we test isospin observables ranging from nucleon/cluster emissions to
collective flows (in particular the elliptic, squeeze out, part). The effects
of the competition between stiffness and momentum dependence of the Symmetry
Potential on the reaction dynamics are thoroughly analyzed. In this way we try
to shed light on the controversial neutron/proton effective mass splitting at
high baryon and isospin densities. New, more exclusive, experiments are
suggested.Comment: 10 pages, 16 figures, new figure added, accepted for publication in
Phys.Rev.
Comparison of dynamical multifragmentation models
Multifragmentation scenarios, as predicted by antisymmetrized molecular
dynamics (AMD) or momentum-dependent stochastic mean-field (BGBD) calculations
are compared. While in the BGBD case fragment emission is clearly linked to the
spinodal decomposition mechanism, i.e. to mean-field instabilities, in AMD
many-body correlations have a stronger impact on the fragmentation dynamics and
clusters start to appear at earlier times. As a consequence, fragments are
formed on shorter time scales in AMD, on about equal footing of light particle
pre-equilibrium emission. Conversely, in BGBD pre-equilibrium and fragment
emissions happen on different time scales and are related to different
mechanisms
Definition of a resistojet control system for the Manned Orbital Research Laboratory. Volume 5 - Resistojet design and Development Final report
Resistojet design and development for Manned Orbital Research Laborator
On the spin-isospin decomposition of nuclear symmetry energy
The decomposition of nuclear symmetry energy into spin and isospin components
is discussed to elucidate the underlying properties of the NN bare interaction.
This investigation was carried out in the framework of the
Brueckner-Hartree-Fock theory of asymmetric nuclear matter with consistent two
and three body forces. It is shown the interplay among the various two body
channels in terms of isospin singlet and triplet components as well as spin
singlet and triplet ones. The broad range of baryon densities enables to study
the effects of three body force moving from low to high densities.Comment: 8 pages, 4 figure
Definition of a resistojet control system for the manned orbital research laboratory. Addendum to volume 5 - 720 hour resistojet life test Final report
Life test data for resistojet thrustors operating with ammonia or hydroge
Hadron production from quark coalescence and jet fragmentation in intermediate energy collisions at RHIC
Transverse momentum spectra of pions, protons and antiprotons in Au+Au
collisions at intermediate RHIC energy of GeV are studied in
a model that includes both quark coalescence from the dense partonic matter and
fragmentation of the quenched perturbative minijet partons. The resulting
baryon to meson ratio at intermediate transverse momenta is predicted to be
larger than that seen in experiments at higher center of mass energies.Comment: 6 pages, 2 figures. Figures replaced to differentially address the
high-pT behavior of baryon versus antibaryon to meson ratio
Transport properties of isospin effective mass splitting
We investigate in detail the momentum dependence () of the effective in
medium Nucleon-Nucleon () interaction in the isovector channel. We focus
the discussion on transport properties of the expected neutron-proton ()
effective mass splitting at high isospin density. We look at observable effects
from collective flows in Heavy Ion Collisions () of charge asymmetric
nuclei at intermediate energies. Using microscopic kinetic equation simulations
nucleon transverse and elliptic collective flows in collisions are
evaluated. In spite of the reduced charge asymmetry of the interacting system
interesting effects are revealed. Good observables, particularly
sensitive to the -mass splitting, appear to be the differences between
neutron and proton flows. The importance of more exclusive measurements, with a
selection of different bins of the transverse momenta () of the emitted
particles, is stressed. In more inclusive data a compensation can be expected
from different -contributions, due to the microscopic
structure of the nuclear mean field in asymmetric matter.Comment: 18 pages, 11 figure
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