TY  - GEN
AV  - public
TI  - Electron-Pair Production in 158 AGeV/c  Pb-Au Collisions from CERES
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/6558/
Y1  - 2006///
KW  - CERES 
KW  -  Elektronenpaaren 
KW  -  ioneninduzierten Kollisionen 
KW  -  Dileptonenpaaren 
KW  -  TPC 
KW  -  $\rho$-Meson 
KW  -  NA45 
KW  -  SPS 
KW  -  CERNHeavy Ion physics dileptons 
KW  -  electron pair 
KW  -  CERES 
KW  -  NA45 
KW  -  QGP 
KW  -  production 
KW  -  TPC 
KW  -  RICH 
KW  -  SDD 
KW  -  electron identification 
KW  -  track finding
A1  - Yurevich, Sergey
N2  - 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.
ID  - heidok6558
ER  -