Please note: This program is currently over-subscribed. You may still apply for the conference, however.
DESCRIPTION AND
RATIONALE: By spring 2002, we expect that the
Relativistic Heavy Ion Collider(RHIC) at Brookhaven will be providing
mature data, and the time will be right for a multi-faceted program to
understand the implications of RHIC for QCD and of QCD for RHIC. RHIC
offers the potential to yield a deeper understanding of new phases of QCD,
of the spin of the proton, and of the dynamics of gauge theories more
generally, particularly under extreme and nonequilibrium conditions. For
this potential to be realized, an integrated theoretical approach along
several directions is required. Perturbative QCD and small-x physics
are necessary ingredients for an understanding of the early stage of
nuclear collisions and of various spin asymmetries; nonequilibrium field
theory methods, both analytical and numerical, are required in this
pre-thermalization stage as well. As the plasma approaches local
equilibrium, QCD thermodynamics as studied perturbatively, by Euclidean
lattice methods, and by appealing to universality and to models which
capture some features of the QCD phase diagram, should become applicable.
The final stages of a RHIC collision are best described in terms of
hadrons; this guarantees that understanding RHIC phenomena requires input
from phenomenological approaches which have been developed to understand
the dynamics of, and observables in, lower energy heavy ion collisions.
The experimental results from RHIC will require all of these ingredients,
and hence, a more comprehensive, integrated theoretical framework firmly
based on QCD for their interpretation than has been developed until now.
The renaissance of interest in the dynamics of gauge theories, which
the advent of experimental data from RHIC can and should accelerate,
provides a good example of recent developments which must become a part of
this framework. There has been a growing recognition of the need to
develop theoretical methods to study field theories under extreme
nonequilibrium conditions, i.e. in real time. While their
motivations have been as diverse as the intended applications, ranging
from phase transitions in the early universe and electroweak baryogenesis
to Bose condensation in gases and vortex dynamics in superconductors, the
basic theoretical tools being developed in these apparently unrelated
areas are precisely the same as those required to describe the
quark-gluon plasma phase of QCD, which will be produced and probed at
RHIC. In each of these cases one has to treat in a consistent theoretical
framework such dynamical issues as soft collective excitations and the
validity of the quasi-particle approximation, transport processes, quantum
decoherence and damping effects, thermalization, the approach to
equilibrium and the emergence of hydrodynamic behavior from microscopic
physics. Many field theorists working on problems such as these, which are
of direct relevance to RHIC physics have not been actively engaged in the
phenomenology of heavy ion collisions; we expect this to change as RHIC
comes on line, and would like to use this ITP program two years from now
to serve as a catalyst for that change. Expertise in nonequilibrium
and gauge theory dynamics gleaned in other contexts could be of
considerable value in understanding the implications of RHIC phenomena for
QCD, but this can only happen if the more theoretically minded keepers of
this expertise understand what the interesting phenomenological questions
are, while at the same time conveying the power of newly developed methods
to those who already have a good sense of the phenomenology. Thus, a major
goal of our program will be to provide a sharp focus in the form of the
concrete problems posed by the RHIC data for the best theoretical methods
in gauge theories under extreme nonequilibrium conditions |