title: Electron-Pair Production in 158 AGeV/c  Pb-Au Collisions from CERES
creator: Yurevich, Sergey
subject: ddc-530
subject: 530 Physics
description: The CERES experiment is devoted to the measurement of  low-mass electron pairs in proton and ion-induced collisions at the  Super Proton Synchrotron accelerator. The main goal of the CERES experiment is to investigate modifications of hadron properties in  hot and dense nuclear matter. A significant enhancement of  dilepton pair yield with respect to expectations based on hadron decays was observed in the mass range 0.25~$<~$m$_{ee}~<$~0.7~GeV/c$^2$. This fascinating result can only be described by models invoking in-medium modifications of the $\rho$ meson. To distinguish between different theoretical explanations of the enhancement the experiment was upgraded in 1998 by the addition of a radial TPC to improve the mass resolution in the vector meson region. In this thesis, the analysis of the data sample taken in 2000 in 158~A~GeV/c Pb-Au collisions with the upgraded experimental setup  is presented. The observed enhancement of the $e^+e^-$ pairs confirms  previous results of CERES. The data, compared to the theoretical calculations based on dropping $\rho$ mass approach and in-medium $\rho$ spectral function modifications, favor the latter.
date: 2006
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/6558/1/thesis.pdf
identifier: DOI:10.11588/heidok.00006558
identifier: urn:nbn:de:bsz:16-opus-65584
identifier:   Yurevich, Sergey  (2006) Electron-Pair Production in 158 AGeV/c Pb-Au Collisions from CERES.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/6558/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng