Bose-Einstein Correlations for Expanding Finite Systems

There are two length-scales present simultaneously in all the principal directions for three-dimensionally expanding, finite systems. These are discussed in detail for the case of a longitudinally expanding system with a transverse flow and a transverse temperature profile. For systems with large geometrical sizes we find an $m_t$-scaling for the parameters of the Bose-Einstein correlation function, which may be valid in the whole transverse mass region for certain model parameters. In this limit, the Bose-Einstein correlations view only a small part of the source. The large geometrical sizes can be inferred from a simultaneous analysis of the invariant momentum distribution and the Bose-Einstein correlation function. A preliminary analysis of the NA44 data indicates that instead of a small fireball we are observing a big and expanding snowball in $S + Pb$ reactions at CERN SPS energies.Comment: 5 pages, no figures, ReVTeX, uses espcrc1.sty, Quark Matter'95 conference, Nucl. Phys. A in pres

Bose-Einstein Correlations for Expanding Finite Systems or from a Hot Fireball to a Snow-Flurry

Most boson emitting sources contain a core of finite dimensions surrounded by a large halo, due to long-lived resonances like $\omega,\eta,\eta',K^{0}$ etc. When the Bose-Einstein correlation (BEC) function of the core can be determined we show that its intercept ($\lambda$) measures, as a function of momentum, the square of the fraction of core particles produced. A simultaneos measurement of BEC and the single-particle distributions can thus determine the characteristics of the core. If the geometrical sizes of the core are sufficiently large the parameters of the BEC function obey the $m_{t}$-scaling observed in $SPb$ and $PbPb$ reactions at CERN. The model can describe the measurements of the single- and two-particle distributions in the central region of $SPb$ reactions. A fit to experimental data shows that the freeze-out of hadrons occurs at a larger volume and at a much lower temperature than that given by the measurement of the inverse slope of the $m_{t}$-spectrum and standard BEC analysis.Comment: ReVTeX, LaTeX, 21 pages, one table, no figures; Proceedings of the International Symposium on Quantum Interferometry Studies in High Energy Nuclear Collisions, 18-20 April, 1995, Hiroshima, Japan, in pres

A hint at quark deconfinement in 200 GeV Au+Au data at RHIC

We give the emission function of the axially symmetric Buda-Lund hydro model and present its simultaneous, high quality fits to identified particle spectra, two-particle Bose-Einstein or HBT correlations and charged particle pseudorapidity distributions as measured by BRAHMS and PHENIX in 0-30 % central, \sqrt{s_{\NN}} = 200 GeV Au+Au collisions at RHIC. The best fit is achieved when the most central region of the particle emitting volume is superheated to $T_0 = 200 \pm 9$ MeV $\ge T_c =172 \pm 3$ MeV, a preliminary, 3 $\sigma$ effect.Comment: 10 pages, 3 figures, talk of A. Ster at the 2nd Warsaw Meeting on Correlations and Resonances in HIC, see http://hirg.if.pw.edu.pl/en/meeting/oct2003/talks/csorgo/Ster.pp

Understanding the rapidity dependence of the elliptic flow and the HBT radii at RHIC

The pseudo-rapidity dependence of the elliptic flow at various excitation energies measured by the PHOBOS Collaboration in Au+Au collisions at RHIC is one of the surprising results that has not been explained before in terms of hydrodynamical models. Here we show that these data are in agreement with theoretical predictions and satisfy the universal scaling relation predicted by the Buda-Lund hydrodynamical model, based on exact solutions of perfect fluid hydrodynamics. We also show a theoretical prediction on the rapidity and transverse momentum scaling of the HBT radii measured in heavy ion collisions, based on the Buda-Lund model.Comment: 6 pages, 2 figures, proceedings contribution for M. Csanad's talk at the Workshop on Particle Correlations and Femtoscopy 2005, Kromeri