791 research outputs found
Freezeout of resonances and nuclear fragments at RHIC
We quantify the conditions at which ``composites'', the resonances and bound
states are produced at RHIC. Using Hubble-like model for late stages,
one can analytically solve the rate equations and also calculate the relevant
optical depth factors. We calculate also the modification of masse and
width, and predict a radiacal shape change of .Comment: 6 pages, proccedings of 19th Winter Workshop on Nuclear Dynamics,
Breckenridge, Colorado, February 200
QCD phases at high density and instantons
The talk is an introduction into diquark condensation phenomena which occur
in QCD at high energy density. They are driven by instantons and
instanton-antiinstanton pairs (or ``molecules''), which generate attraction in
some qq channels. A number of phases is possible, with or without restoration
of chiral symmetry: the work is not finished and we do not yet know which take
place in real QCD. We also emphasize that specific diquark correlations play a
significant role in baryon structure, in particular making that of a nucleon
very different of a (or other member of a decuplet). This ``small
'' scenario based on comparison to QCD with two colors is contrasted with
the ``large '' one.Comment: invited talk at "QCD at finite baryon density", Bielefeld, 199
Anisotropy of photon production: Initial eccentricity or magnetic field
Recent measurements of the azimuthal anisotropy of direct photons in
heavy-ion collisions at the energies of RHIC show that it is of the same order
as the hadronic one. This finding appears to contradict the expected dominance
of photon production from a quark-gluon plasma at an early stage of a heavy-ion
collision. A possible explanation of the strong azimuthal anisotropy of the
photons, given recently, is based on the presence of a large magnetic field in
the early phase of a collision. In this letter, we propose a method to
experimentally measure the degree to which a magnetic field in heavy-ion
collisions is responsible for the observed anisotropy of photon production. The
experimental test proposed in this letter may potentially change our
understanding of the non-equilibrium stage and possible thermalization in
heavy-ion collisions.Comment: 4 pages, 3 figures; version accepted for publication: discussions
extended, MC calculations adde
Strongly Coupled Quark-Gluon Plasma: The Status Report
RHIC data have shown robust collective flows, strong jet and charm quenching,
and charm flow.
Recently ``conical flows'' from damped jets were seen. Non-Abelian classical
strongly coupled plasmas were introduced and studied via molecular dynamics,
with first results for its transport (diffusion and viscosity) reported.
Quantum-mechanical studies reveal the survival for of the lowest
binary states, including colored ones, and also of some manybody ones such as
baryons. ``Polymeric chains'' are also bound in some range of
, perhaps the progenitors of the QCD strings.
AdS/CFT applications advanced to a completely new level of detail: they now
include studies of thermal heavy quark motion, jet quenching and even conical
flow. Confinement is however still beyond simply strong coupling: its de-facto
inclusion the so called AdS/QCD approach is so far added as a model, while true
understanding may probably only come from further insights into the monopole
dynamics.Comment: It is brief review of the field, in 14 pages, written for proceedings
of Continuous Advances in QCD, April 2006. As the progress is very rapid, it
includes several new papers which appeared between April and August. The
version 2 has more references and few statements get clarified bette
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