Effects of collective expansion on light cluster spectra in relativistic heavy ion collisions

We discuss the interplay between collective flow and density profiles, describing light cluster production in heavy ion collisions at very high energies. Calculations are performed within the coalescence model. We show how collective flow can explain some qualitative features of the measured deuteron spectra, provided a proper parametrization of the spatial dependence of the single particle phase space distribution is chosen.Comment: 11 pages Latex, 2 figures, to be published in Phys. Lett.

Rho meson properties in the Nambu-Jona-Lasinio model

Some properties of the rho vector meson are calculated within the Nambu-Jona-Lasinio model, including processes that go beyond the random phase approximation. To classify the higher order contributions, we adopt $1/N_c$ as expansion parameter. In particular, we evaluate the leading order contributions to the $\rho \rightarrow \pi \pi$ decay width, obtaining the value $\Gamma = 118$ MeV, and to the shift of the rho mass which turns out to be lowered by 64 MeV with respect to its RPA value. A set of model parameters is determined accordingly.Comment: 21 pages Latex, 4 figures, to be published in Z. Phys.

Reconstruction of the Proton Source in Relativistic Heavy Ion Collisions

We describe a direct method to reconstruct the transverse proton source formed in a relativistic heavy ion collision, making use of experimentally measured proton and deuteron spectra and assuming that deuterons are formed via two-nucleon coalescence. We show that an ambiguity with respect to the source temperature still persists and we indicate a possible solution to the problem

Multifragmentation of non-spherical nuclei

The shape influence of decaying thermalized source on various characteristics of multifragmentation as well as its interplay with effects of angular momentum and collective expansion are first studied and the most pertinent variables are proposed. The analysis is based on the extension of the statistical microcanonical multifragmentation model.Comment: 5 pages, 4 figure

Probing the QCD Equation of State

We propose a novel quasiparticle interpretation of the equation of state of deconfined QCD at finite temperature. Using appropriate thermal masses, we introduce a phenomenological parametrisation of the onset of confinement in the vicinity of the phase transition. Lattice results of bulk thermodynamic quantities are well reproduced, the extension to small quark chemical potential is also successful. We then apply the model to dilepton production and charm suppression in ultrarelativistic heavy-ion collisions.Comment: 6 pages, 8 figures. Invited talk presented by R. A. Schneider at the XVI International Conference on Particles and Nuclei (PANIC02), Osaka, Japan, September 30 - October 4, 200

Anomalous radial expansion in central heavy-ion reactions

The expansion velocity profile in central heavy-ion reactions in the Fermi energy domain is examined. The radial expansion is non-hubblean and in the surface region it scales proportional to a higher exponent ($\alpha > 1$) of the radius. The anomalous expansion velocity profile is accompanied by a power law nucleon density profile in the surface region. Both these features of central heavy-ion reactions disappear at higher energies, and the system follows a uniform Hubble expansion ($\alpha \simeq 1$)