288 research outputs found
From kinetic theory to dissipative fluid dynamics
We present the results of deriving the Israel-Stewart equations of
relativistic dissipative fluid dynamics from kinetic theory via Grad's
14-moment expansion. Working consistently to second order in the Knudsen
number, these equations contain several new terms which are absent in previous
treatments.Comment: 7 pages, proceedings of the Erice School on Nuclear Physics "Heavy
Ion collisions from the Coulomb Barrier up to the Quark Gluon Plasma", Erice,
Sicily, Sep. 16 - 24, 200
Phase diagram of neutral quark matter at moderate densities
We discuss the phase diagram of moderately dense, locally neutral
three-flavor quark matter using the framework of an effective model of quantum
chromodynamics with a local interaction. The phase diagrams in the plane of
temperature and quark chemical potential as well as in the plane of temperature
and lepton-number chemical potential are discussed.Comment: 32 pages, 11 figures; contribution to the proceedings of the INT
workshop "Pairing in fermionic systems", Seattle, September 19-23, 200
The phase diagram of neutral quark matter: The effect of neutrino trapping
We study the effect of neutrino trapping on the phase diagram of dense,
locally neutral three-flavor quark matter within the framework of a
Nambu--Jona-Lasinio model. In the analysis, dynamically generated quark masses
are taken into account self-consistently. The phase diagrams in the plane of
temperature and quark chemical potential, as well as in the plane of
temperature and lepton-number chemical potential are presented. We show that
neutrino trapping favors two-flavor color superconductivity and disfavors the
color-flavor-locked phase at intermediate densities of matter. At the same
time, the location of the critical line separating the two-flavor
color-superconducting phase and the normal phase of quark matter is little
affected by the presence of neutrinos. The implications of these results for
the evolution of protoneutron stars are briefly discussed.Comment: 10 pages, 9 figures, references added; version accepted for
publication in Phys. Rev.
The phase diagram of neutral quark matter: Self-consistent treatment of quark masses
We study the phase diagram of dense, locally neutral three-flavor quark
matter within the framework of the Nambu--Jona-Lasinio model. In the analysis,
dynamically generated quark masses are taken into account self-consistently.
The phase diagram in the plane of temperature and quark chemical potential is
presented. The results for two qualitatively different regimes, intermediate
and strong diquark coupling strength, are presented. It is shown that the role
of gapless phases diminishes with increasing diquark coupling strength.Comment: 10 pages, 7 figures. Two new figures added as in the published
versio
Results from RHIC with Implications for LHC
Results from the PHENIX experiment at RHIC in p-p and Au+Au collisions are
reviewed from the perspective of measurements in p-p collisions at the CERN-ISR
which serve as a basis for many of the techniques used. Issues such as J/Psi
suppression and hydrodynamical flow in A+A collisions require data from
LHC-Ions for an improved understanding. Suppression of high pT particles in
Au+Au collisions, first observed at RHIC, also has unresolved mysteries such as
the equality of the suppression of inclusive pi0 (from light quarks and gluons)
and direct-single electrons (from the decay of heavy quarks) in the transverse
momentum range 4< pT < 9 GeV/c. This disfavors a radiative explanation of
suppression and leads to a fundamental question of whether the Higgs boson
gives mass to fermions. Observation of an exponential distribution of direct
photons in central Au+Au collisions for 1< pT <2 GeV/c where hard-processes are
negligible and with no similar exponential distribution in p-p collisions
indicates thermal photon emission from the medium at RHIC, making PHENIX at the
moment ``the hottest experiment in Physics''.Comment: Invited lectures at the International School of Subnuclear Physics,
47th Course, "The most unexpected at LHC and the status of High Energy
Frontier'', Erice, Sicily, Italy, August 29-September 7. 2009. 32 pages, 22
figure
Vacuum phenomenology of the chiral partner of the nucleon in a linear sigma model with vector mesons
We investigate a linear sigma model with global chiral symmetry. The mesonic degrees of freedom are the standard scalar and
pseudoscalar mesons and the vector and axial-vector mesons. The baryonic
degrees of freedom are the nucleon, , and its chiral partner, , which
is usually identified with N(1535). The chiral partner is incorporated in the
so-called mirror assignment, where the nucleon mass is not solely generated by
the chiral condensate but also by a chirally invariant mass term, . The
presence of (axial-) vector fields modifies the expressions for the axial
coupling constants of the nucleon, , and its partner,
. Using experimental data for the decays and
, as well as lattice results for we infer
MeV, i.e., an appreciable amount of the nucleon mass originates
from sources other than the chiral condensate. We test our model by evaluating
the decay and the s-wave nucleon-pion scattering lengths
.Comment: 16 pages, 2 figures. To appear in Phys. Rev.
Simple solutions of fireball hydrodynamics for self-similar elliptic flows
Simple, self-similar, elliptic solutions of non-relativistic fireball
hydrodynamics are presented, generalizing earlier results for spherically
symmetric fireballs with Hubble flows and homogeneous temperature profiles. The
transition from one dimensional to three dimensional expansions is investigated
in an efficient manner.Comment: 12 pages, 4 figures in 8 .eps files, references to recent data added,
accepted in Physics Letters
Effective Gap Equation for the Inhomogeneous LOFF Superconductive Phase
We present an approximate gap equation for different crystalline structures
of the LOFF phase of high density QCD at T=0. This equation is derived by using
an effective condensate term obtained by averaging the inhomogeneous condensate
over distances of the order of the crystal lattice size. The approximation is
expected to work better far off any second order phase transition. As a
function of the difference of the chemical potentials of the up and down
quarks, , we get that the octahedron is energetically favored from
to , where is the gap for
the homogeneous phase, while in the range the face
centered cube prevails. At a first order phase
transition to the normal phase occurs.Comment: 11 pages, 5 figure
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