Program of talks
*) Each talk is followed by a discussion session (duration
about 30 minutes) and a coffee break.
- Quantum and classical fields far
from equilibrium: an overview
- The current status of quantum and classical fields far from
equilibrium is reviewed. Among other things, I'll discuss the
limitations of mean-field approximations, the importance of
classical field theory to benchmark truncation schemes, and
the recent progress made using the 2PI effective action.
- Close to equilibrium: transport
coefficients and spectral functions
- Some recent results on transport coefficients and spectral
functions in thermal field theory are presented. I'll discuss
transport coefficients from a diagrammatic approach, the relevance
of Ward identities, the relation between transport coefficients and
the 2PI effective action, and the use of lattice QCD. I'll also
mention a nonperturbative approach to the computation of spectral
functions in the classical limit.
- Anisotropic flow in relativistic heavy-ion collisions
- I will introduce the subject of Anisotropic Flow with a particular
emphasis on flow as a probe of equilibration of the matter produced in
relativistic heavy-ion collisions. I will then describe our recent
work on the question of what is the best way to analyse the flow data
and extract the genuine flow free of spurious effects. I will also try
to summarise the experimental and theoretical status of the field.
- Thermodynamics of the high temperature QGP
- I describe weak coupling calculations of high temperature QGP thermodynamics.
The failure of perturbation theory and the need for resummation is shown. The
skeleton graph expansion and an approximately self-consistent treatment which
gives the entropy of the QGP is explained.
- Download the talk (PPT: 3484 Kbytes)
- Download the talk (PDF: 19.2 Mbytes)
- Quantum transport and Yang-Mills fields
- I describe some recent developments in close to equilibrium field
theory. For non-abelian gauge fields there are strongly coupled
field modes even in the limit of weak gauge couplings. Using perturbation
theory and 'renormalization group' techniques one can disentangle the
dynamics of weakly and strongly coupled degrees of freedom and obtain
effective theories for the strongly coupled ones. I also discuss the
possibilities for lattice simulations of these effective theories.
- The Wroblewski parameter from lattice QCD
- Enhancement of strangeness production has since long been proposed as a
promising signal of quark-gluon plasma production. A convenient indicator
for it is the Wroblewski parameter which has been shown to be about a
factor two higher in heavy ion collisions. Using a method proposed by us
earlier, lattice QCD results for the Wroblewski parameter have been
obtained from our simulations of QCD with two light quarks both below and
above the chiral transition. Our first principles based and parameter
free result for the high temperature phase agrees will with the A-A data.
Our results also indicate lower value for the low temperature phase which
seems to need bigger lattices to pin it down precisely.
- Download the talk (PDF: 496 Kbytes)
- The electrical conductivity of
the QCD plasma: a lattice study
- The electrical conductivity in the hot phase of the QCD plasma is
extracted from a quenched lattice measurement of the Euclidean time
vector correlator for 1.5<T/Tc<3. The spectral density in the
vicinity of the origin is analysed using a method specially adapted
to this region, and a peak at small energies is seen. The vector
susceptibility is then used to extract the electrical conductivity
and make a continuum extrapolation. This allows us to predict the
soft photon emissivity of the QCD plasma.
- Download the talk (PDF: 212 Kbytes)
- The speed of sound in the QCD plasma
- We report the continuum limit of the speed of sound in a QCD plasma
immediately for 1.5<T/Tc<3. The results are 20-25% lower than
for an ideal gas in the full range of temperature. We also report
the specific heat at constant volume in the same range of temperature.
The lattice measurements are made at lattice spacings small enough
for the perturbative beta-function to suffice.
- Download the talk (PPT: 336 Kbytes)
- Lattice QCD approach for finite density
and finite temperature system
- We report our works to understand QCD dynamics at finite temperature
and density. Since such system may be realized in high energy heavy ion
collisions and inside nuclear matter in laboratories, we investigate
mainly around regions which can be covered in such experiments. We
discuss hadron mass behavior around $(T=T_c, \mu=0)$ including both pole
and screening masses, gluon screening mass at $T=T_c \sim 5T_c$, and QGP
transport coefficients. We briefly discuss other approaches to understand
QCD at high density.
- Download the talk (PPT: 864 Kbytes)
- Production mechanism for quark-gluon plasma
in heavy-ion collisions
- In this talk, I outline a framework to describe the production process
of quarks and gluons in heavy ion collisions. Based on simple and yet
general considerations, the mechanism that we propose is shown to
incorporate the dynamical nature of the color charge, the non-Markovian
nature of production, and the dynamical role played by the vacuum.
As illustrations, the production rate in the compact part of the phase
space (corresponding to the color) and the configuration space will be
- Taylor expansion in chemical potential:
the Wroblewski parameter
- In this talk, I present a systematic Taylor expansion of the quark
condensate with chemical potential. A Maxwell relation then allows
us to connect this with the mass dependence of the Wroblewski parameter.
- Download the talk (PDF: 3484 Kbytes)
- Let the partons cascade
- We discuss the re-formulation of the parton cascade model,
taking into account recent advances in our understanding
of saturation and screening. Results for energy density,
screening mass, photons, and net baryons are discussed and
future directions indicated.
- Large mass and chemical potential model
- We discuss a model based on the hopping parameter expansion in QCD.
Although this still has the sign problem, it can serve as a laboratory
for QCD at large matter density.
- Download the talk (PDF: 464 Kbytes)
Created on Nov 18, 2003.
Last modified on Dec 12, 2003.