A new phase of matter in Oakland
Recent results from the Relativistic Heavy Ion Collider (RHIC) and the phase diagram of matter at very high energies were the focal points of Quark Matter 2004, held January 10-17, 2004 in the Oakland, California convention center. About 700 participants, including 125 students, from 28 countries gathered for 5 days of plenary and parallel sessions. Besides the scientific discussions, participants enjoyed an afternoon of excursions; choices included visits to San Francisco, the Muir woods, and, of course, a chance to sample Napa Valley wines. There was also a day of introductory lectures for graduate students and a separate afternoon program for 50 local high school teachers. The ''Quark Matter'' conference series has evolved into the premier venue for relativistic heavy ion collisions, and QM2004 was no exception. The 44 plenary and 92 parallel session talks featured a veritable flood of data from STAR (Kai Schweda, LBNL), PHENIX (Tony Frawley, Florida State), PHOBOS (Peter Steinberg, BNL) and BRAHMS (Michael Murray, Kansas), at RHIC. This was accompanied by contributions from HERMES ( Pasquale DiNezza, Frascati) and HERA-B (Joakim Spengler, Heidelberg) and continuing analyses from NA-49 (Marek Gazdzicki, Frankfurt) and NA-57 (Giuseppe Bruno, Bari) at the CERN SPS. The theoretical contributions presented a broad range of models and calculations, from microscopic particle-by-particle simulations to hydrodynamic models that model the bulk behavior using an equation of state. A focus of much discussion was the question ''Have we found the Quark Gluon Plasma (QGP)?'' This search was the prime motivation to build RHIC. Although the RHIC experiments made no formal statement, most conference attendees seemed to feel that the answer was yes. No single measurement makes the case, but the variety of data featured at QM2004 seems most easily explained in the context of a QGP. Some of the signatures included the suppression of high transverse momentum (pT) particles and, disappearance of back-to-back correlated high-pT particles (showing that produced particles underwent very strong energy loss before escaping from the medium), the strong elliptical flow (showing that the pressure was very high early in the collision), and the species dependent elliptical flow (showing behavior as an almost perfect fluid, as expected for a QGP). Data on deuterium-gold collisions presented at QM2004 provided important cross-checks, ruling out models that explained the observed phenomena as initial-state effects present in the undisturbed gold nuclei. Many of these signatures were reviewed in the 5 rapporteur talks covering high-pT and jets (Kirill Filimonov, LBNL), bulk properties and collective flow (Zhangbu Xu, BNL), correlations and HBT (Harald Appelhauser, GSI), leptons, photons and heavy quarks (Ralf Averbeck, Stony Brook) and theory (Ralf Rapp, Texas A & M). In addition, Mike Lisa (Ohio State), Miklos Gyulassy (Colombia) and Peter Braun-Munzinger (GSI) gave their personal views on the QGP.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of NuclearPhysics
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 862334
- Report Number(s):
- LBNL-58256; R&D Project: NRNC; BnR: KB0201022; TRN: US0600656
- Journal Information:
- Nuclear Physics News, Vol. 13, Issue 3; Related Information: Journal Publication Date: October,2004
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
CERN
COLOMBIA
EDUCATIONAL FACILITIES
FLOODS
GOLD
HEAVY IONS
HYDRODYNAMIC MODEL
LEPTONS
NUCLEI
PHASE DIAGRAMS
PHOTONS
QUARK MATTER
QUARKS
STARS
TRANSVERSE MOMENTUM
Quark Matter heavy-ions phase change