900 research outputs found
From SPS to RHIC: Breaking the Barrier to the Quark-Gluon Plasma
After 15 years of heavy-ion collision experiments at the AGS and SPS, the
recent turn-on of RHIC has initiated a new stage of quark-gluon plasma studies.
I review the evidence for deconfined quark-gluon matter at SPS energies and the
recent confirmation of some of the key ideas by the new RHIC data. Measurements
of the elliptic flow at RHIC provide strong evidence for efficient
thermalization during the very early partonic collision stage, resulting in a
well-developed quark-gluon plasma with almost ideal fluid-dynamical collective
behaviour and a lifetime of several fm/c.Comment: LaTex 12 pages, including 6 figures. Opening talk at the Conference
"QCD@work", Martinafranca (Bari), June 16-20, 200
Thermalization at RHIC
Ideal hydroynamics provides an excellent description of all aspects of the
single-particle spectra of all hadrons with transverse momenta below about
1.5-2 GeV/c at RHIC. This is shown to require rapid local thermalization at a
time scale below 1 fm/c and at energy densities which exceed the critical value
for color deconfinement by an order of magnitude. The only known thermalized
state at such energy densities is the quark-gluon plasma (QGP). The rapid
thermalization indicates that the QGP is a strongly interacting liquid rather
than the weakly interacting gas of quarks and gluons that was previously
expected.Comment: Erroneous formulation on p.2 corrected. 16 pages, incl. 4 postscript
figures. Invited talk presented at HADRON-RANP 2004 (IX Hadron Physics and
VII Relativistics Aspects of Nuclear Physics: A Joint Meeting on QCD and
QGP), Angra dos Reis, Rio de Janeiro, Brazil, March 28 - April 3, 2004. To
appear in AIP Conference Proceedings (M. Bracco, M. Chiapparini, et al.,
eds.
Event-by-event hydrodynamics for heavy-ion collisions
We compare v2/{\epsilon}2 and v3/{\epsilon}3 from single-shot and
event-by-event (2+1)-dimensional hydrodynamic calculations and discuss the
validity of using single-shot calculations as substitutes for event-by-event
calculations. Further we present a proof- of-concept calculation demonstrating
that v2 and v3 together can be used to strongly reduce initial condition
ambiguities.Comment: 3 pages, 2 figures. Contribution to the proceedings for 19th
Particles & Nuclei International Conference (PANIC11
Collective flow and viscosity in relativistic heavy-ion collisions
Collective flow, its anisotropies and its event-to-event fluctuations in
relativistic heavy-ion collisions, and the extraction of the specific shear
viscosity of quark-gluon plasma (QGP) from collective flow data collected in
heavy-ion collision experiments at RHIC and LHC are reviewed. Specific emphasis
is placed on the similarities between the Big Bang of our universe and the
Little Bangs created in heavy-ion collisions.Comment: 38 pages (incl. 11 figures), 145 references. Invited review prepared
for Annual Review in Nuclear and Particle Physics 63 (2013
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