What can we learn from three-pion interferometry ?

We address the question which additional information on the source shape and dynamics can be extracted from three-particle Bose-Einstein correlations. For chaotic sources the true three-particle correlation term is shown to be sensitive to the momentum dependence of the saddle point of the source and to its asymmetries around that point. For partially coherent sources the three-pion correlator allows to measure the degree of coherence without contamination from resonance decays. We derive the most general Gaussian parametrization of the two- and three-particle correlator for this case and discuss the space-time interpretation of the corresponding parameters.Comment: 16 pages, to be published in Phys. Rev.

Three-Point Functions at Finite Temperature

We study 3-point functions at finite temperature in the closed time path formalism. We give a general decomposition of the eight component tensor in terms of seven vertex functions. We derive a spectral representation for these seven functions in terms of two independent real spectral functions. We derive relationships between the seven functions and obtain a representation of the vertex tensor that greatly simplifies calculations in real time.Comment: 21 pages LaTeX; one ps-figure; Revised version, contains more references and discussio

Testing the Space-Time Structure of Event Generators

We report on work done in collaboration with Klaus Kinder-Geiger and John Ellis which aims at connecting the space-time structure of event generator simulations with observable output.Comment: 16 pages LaTeX, including 5 postscript figures. To appear in the Proceedings of ``RHIC Physics and Beyond - Kay Kay Gee Day'' (Brookhaven National Laboratory, 23 Oct 1998), ed. by B. Muller and R.D. Pisarski, AIP Conference Proceeding

Bose-Einstein Final State Symmetrization for Event Generators of Heavy Ion Collisions

We discuss algorithms which allow to calculate identical two-particle correlations from numerical simulations of relativistic heavy ion collisions. A toy model is used to illustrate their properties.Comment: Talk given at CRIS'98 (Catania, June 8-12, 1998), to appear in "CRIS'98: Measuring the size of things in the Universe: HBT interferometry and heavy ion physics", (S. Costa et al., eds.), World Scientific, Singapore, 1998. (10 pages Latex, 1 eps-figure, extended version of conference proceedings, Fig1 a,b added and corresponding discussion enlarged

Equation of State and Collective Dynamics

This talk summarizes the present status of a program to quantitatively relate data from the Relativistic Heavy Ion Collider (RHIC) on collective expansion flow to the Equation of State (EOS) of hot and dense strongly interacting matter, including the quark-gluon plasma and the quark-hadron phase transition. The limits reached with the present state of the art and the next steps required to make further progress will both be discussed.Comment: 8 pages, 6 two-part figures. Invited talk given at the 5th International Conference on the Physics and Astrophysics of Quark-Gluon Plasma (ICPAQGP 2005), Kolkata (India), Feb 8-12, 2005. Proceedings to be published in Journal of Physics: Conference Series (Jan-E Alam et al., eds.

Fitted HBT radii versus space-time variances in flow-dominated models

The inability of otherwise successful dynamical models to reproduce the ``HBT radii'' extracted from two-particle correlations measured at the Relativistic Heavy Ion Collider (RHIC) is known as the ``RHIC HBT Puzzle.'' Most comparisons between models and experiment exploit the fact that for Gaussian sources the HBT radii agree with certain combinations of the space-time widths of the source which can be directly computed from the emission function, without having to evaluate, at significant expense, the two-particle correlation function. We here study the validity of this approach for realistic emission function models some of which exhibit significant deviations from simple Gaussian behaviour. By Fourier transforming the emission function we compute the 2-particle correlation function and fit it with a Gaussian to partially mimic the procedure used for measured correlation functions. We describe a novel algorithm to perform this Gaussian fit analytically. We find that for realistic hydrodynamic models the HBT radii extracted from this procedure agree better with the data than the values previously extracted from the space-time widths of the emission function. Although serious discrepancies between the calculated and measured HBT radii remain, we show that a more ``apples-to-apples'' comparison of models with data can play an important role in any eventually successful theoretical description of RHIC HBT data.Comment: 12 pages, 16 color figure