The relationship between particle freeze-out distributions and HBT radius parameters

The relationship between pion and kaon space-time freeze-out distributions and the HBT radius parameters in high-energy nucleus-nucleus collisions is investigated. We show that the HBT radius parameters in general do not reflect the R.M.S. deviations of the single particle production points. Instead, the HBT radius parameters are most closely related to the curvature of the two-particle space-time relative position distribution at the origin. We support our arguments by studies with a dynamical model (RQMD 2.4).Comment: RevTex, 10 pages including 3 figures. v2: Discussion of the lambda parameter has been added. PRC, in prin

A stopped Delta-Matter Source in Heavy Ion Collisions at 10 GeV/n

We predict the formation of highly dense baryon-rich resonance matter in Au+Au collisions at AGS energies. The final pion yields show observable signs for resonance matter. The Delta(1232) resonance is predicted to be the dominant source for pions of small transverse momenta. Rescattering effects -- consecutive excitation and deexcitation of Deltas -- lead to a long apparent lifetime (> 10 fm/c) and rather large volumina (several 100 fm^3) of the Delta-matter state. Heavier baryon resonances prove to be crucial for reaction dynamics and particle production at AGS.Comment: 17 pages, 5 postscript figures, uses psfig.sty and revtex.st

Thermal analysis of hadron multiplicities from relativistic quantum molecular dynamics

Some questions arising in the application of the thermal model to hadron production in heavy ion collisions are studied. We do so by applying the thermal model of hadron production to particle yields calculated by the microscopic transport model RQMD(v2.3). We study the bias of incomplete information about the final hadronic state on the extraction of thermal parameters.It is found that the subset of particles measured typically in the experiments looks more thermal than the complete set of stable particles. The hadrons which show the largest deviations from thermal behaviour in RQMD(v2.3) are the multistrange baryons and antibaryons. We also looked at the influence of rapidity cuts on the extraction of thermal parameters and found that they lead to different thermal parameters and larger disagreement between the RQMD yields and the thermal model.Comment: 12 pages, 2 figures, uses REVTEX, only misprint and stylistic corrections, to appear in Physical Review

Comparison of Experimental Data to the Relativistic Quantum Molecular Dynamics Model For Si+Au Collisions at 14.6 A GeV/c

Predictions from the RQMD model are systematically compared to recently published charged hadron distributions of AGS Experiment 802 for central Si+Au collisions at 14.6$A$ GeV/$c$, taking into account both the experimental trigger condition and acceptance. The main features of the data, including K$^+$ production, can be understood quantitatively to better than 20\% within the framework of the model, although several discrepancies are found, most importantly for the proton spectra.Comment: 16 pages (TeX) plus 6 Postscript figures (tar-gz-compressed and uuencoded

Analysis of resonancesinduced by the SIS-18 electron cooler

Besides beam cooling, an electron cooler also acts as a non-linear optical element. This may lead to the excitation of resonances possibly resulting in an increase of the beam emittance. The aim of this work is the calculation of resonances driven by the electron space charge field in the cooler installed in the SIS heavy ion synchrotron at GSI Darmstadt. For our calculations, we used a numerical model consisting of a rotation matrix representing the ideal lattice together with a non-linear transverse kick element representing the electron cooler. Within this model, we studied the dominant resonance lines resulting from the interaction with the cooler