43 research outputs found
Thermodynamics of Deconfined QCD at Small and Large Chemical Potential
We present large QCD/QED as a test bed for improved pressure
calculations, show how to apply the hints obtained on optimized renormalization
scales at large to finite , and compare the results to recent
lattice data.Comment: 5 pages, to appear in the proceedings of SEWM 2004, Helsinki, 16-19
June 200
The pressure of deconfined QCD for all temperatures and quark chemical potentials
A new method for the evaluation of the perturbative expansion of the QCD
pressure is presented which is valid for all temperatures and quark chemical
potentials in the deconfined phase, and worked out up to and including order
g^4. This new approach unifies several distinct perturbative approaches to the
equation of state, and agrees with dimensional reduction, HDL and HTL
resummation schemes, and the zero-temperature result in their respective ranges
of validity.Comment: 4 pages, 5 figures, to appear in the proceedings of Strong and
Electroweak Matter 2006 (SEWM), BNL, May 200
Rapidity profiles from 3+1D Glasma simulations with finite longitudinal thickness
We present our progress on simulating the Glasma in the early stages of heavy
ion collisions in a non-boost-invariant setting. Our approach allows us to
describe colliding nuclei with finite longitudinal width by extending the
McLerran-Venugopalan model to include a parameter for the Lorentz-contracted
but finite extent of the nucleus in the beam direction. We determine the
rapidity profile of the Glasma energy density, which shows strong deviations
from the boost invariant result. Both broad and narrow profiles can be produced
by varying the initial conditions. We find reasonable agreement when we compare
the results to rapidity profiles of measured pion multiplicities from RHIC.Comment: 5+1 pages, 2 figures, prepared for Proceedings of the European
Physical Society Conference on High Energy Physics (EPS-HEP) 201
Broken boost invariance in the Glasma via finite nuclei thickness
We simulate the creation and evolution of non-boost-invariant Glasma in the
early stages of heavy ion collisions within the color glass condensate
framework. This is accomplished by extending the McLerran-Venugopalan model to
include a parameter for the Lorentz-contracted but finite width of the nucleus
in the beam direction. We determine the rapidity profile of the Glasma energy
density, which shows deviations from the boost-invariant result. Varying the
parameters both broad and narrow profiles can be produced. We compare our
results to experimental data from RHIC and find surprising agreement.Comment: 6 pages, 4 figure
Yoctosecond metrology through HBT correlations from a quark-gluon plasma
Expansion dynamics at the yoctosecond timescale affect the evolution of the
quark gluon plasma (QGP) created in heavy ion collisions. We show how these
dynamics are accessible through Hanbury Brown and Twiss (HBT) intensity
interferometry of direct photons emitted from the interior of the QGP. A
detector placed close to the beam axis is particularly sensitive to early polar
momentum anisotropies of the QGP. Observing a modification of the HBT signal at
the proposed FoCal detector of the LHC ALICE experiment would allow to measure
the isotropization time of the plasma and could provide first experimental
evidence for photon double pulses at the yoctosecond timescale.Comment: 5 pages, 3 figure
Yoctosecond photon pulses from quark-gluon plasmas
Present ultra-fast laser optics is at the frontier between atto- and
zeptosecond photon pulses, giving rise to unprecedented applications. We show
that high-energetic photon pulses down to the yoctosecond timescale can be
produced in heavy ion collisions. We focus on photons produced during the
initial phase of the expanding quark-gluon plasma. We study how the time
evolution and properties of the plasma may influence the duration and shape of
the photon pulse. Prospects for achieving double peak structures suitable for
pump-probe experiments at the yoctosecond timescale are discussed.Comment: 4 pages, 2 figures; final version as accepted by PR