Two-Particle Correlations at 40, 80, and 158 AGeV Pb-Au Collisions

In this thesis, a centrality dependent study of tow-particle momentum correlations of like-sign pions (HBT interferometry) from Pb-Au collisions at beam energies of 40, 80 and 158 AGeV is presented. The three-dimensional correlation function C_2, depending on the relative momentum components of the particle pair, was parameterized using a three-dimensional Gaussian, modified to consider the final state Coulomb repulsion. The parameterization was done in the Cartesian out-side-long system as proposed by G. Bertsch and S. Pratt. A differential analysis of the HBT radius parameters as a function of the mean transverse pair momentum k_perp allowed to determine transverse geometrical source sizes of about 5.5 fm to 7 fm, increasing with energy and centrality. The mean transverse flow velocity v_perp was found to be of the order 0.5--0.6 c. For the freeze-out time tau_f values between 6 and 8 fm/c were obtained with a duration of particle emission compatible with zero. The beam energy dependence of the HBT radii provide evidence for a universal pion freeze-out condition. The analyzed data have been recorded with the CERES spectrometer at the Super Proton Synchrotron (SPS) accelerator at CERN.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Heidelberg

Year

2002

Author dc:creator

• Tilsner, Heinz

Contributors dc:contributor

• Stachel, Johanna

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/2474

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:2474