Relativistic Heavy Ion Physics in the New Millennium

The field of relativistic heavy ion physics has seen significant advancement in the new millennium toward a greater understanding of QCD at high temperatures with the commissioning and operation of the Relativistic Heavy Ion Collider. Here we review progress in the field as presented in a set of lectures at the Lake Louise Winter Institute on Fundamental Interactions in February 2004.Comment: 30 pages, 17 figures, Lake Louise Winter Institute on Fundamental Interactions 2004 conference proceeding

First results from RHIC: What are they telling us?

The Relativistic Heavy Ion Collider (RHIC) facility at Brookhaven National Laboratory is the first accelerator specifically constructed for the study of very hot and dense nuclear matter. At sufficiently high temperature, nuclear matter is expected to undergo a phase transition to a quark-gluon plasma. It is the specific goal of the field to study the nature of this plasma and understand the phase transitions between different states. The RHIC accelerator along with four experiments BRAHMS, PHENIX, PHOBOS, and STAR were commissioned last year with first collisions occurring in June 2000. Presented here are the first results from low luminosity beam in Run I. They are a glimpse of the wealth of physics to be extracted from the RHIC program over the next several years.Comment: Invited Talk at the International Nuclear Physics Conference INPC2001, Berkeley, CA, July 29th - August 3rd 200

Strangeness Production as a Diagnostic Tool for Understanding Heavy Ion Reactions

Strangeness production has long been proposed as a diagnostic tool for understanding the dynamics of relativistic heavy ion collisions. In this presentation we review the traditional picture of strangeness enhancement as a signature for quark-gluon plasma formation. We then review, in order, some experimental data on strange particle production in $e^{+}e^{-}$, $pp$, $p\bar{p}$, proton-nucleus and nucleus-nucleus collisions. This is not a comprehensive review, but rather an emphasis of a few significant points. Any clear interpretation of strange particle yields measured in heavy ion reactions is impossible without a physical understanding of the production mechanisms in elementary particle collisions.Comment: 6 pages, 2 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn

Particle spectra and HBT radii for simulated central nuclear collisions of C+C, Al+Al, Cu+Cu, Au+Au, and Pb+Pb from Sqrt(s)=62.4-2760 GeV

We study the temperature profile, pion spectra and HBT radii in central symmetric and boost-invariant nuclear collisions using a super hybrid model for heavy-ion collisions (SONIC) combining pre-equilibrium flow with viscous hydrodynamics and late-stage hadronic rescatterings. In particular, we simulate Pb+Pb collisions at Sqrt(s)=2.76 TeV, Au+Au, Cu+Cu, Al+Al, and C+C collisions at Sqrt(s)=200 GeV and Au+Au, Cu+Cu collisions at Sqrt(s)=62.4 GeV. We find that SONIC provides a good match to the pion spectra and HBT radii for all collision systems and energies, confirming earlier work that a combination of pre-equilibrium flow, viscosity and QCD equation of state can resolve the so-called HBT puzzle. For reference, we also show p+p collisions at Sqrt(s)=7 TeV. We make tabulated data for the 2+1 dimensional temperature evolution of all systems publicly available for the use in future jet energy loss or similar studies.Comment: 9 pages, 5 figures, 2 tables; v2: fixed typos, updated figures; v3: minor changes, matches published versio