High transverse momentum hadron spectra at √sNN=17.3 GeV in Pb+Pb and p+p collisions

Fachbereich Physik, Universität, Marburg, Germany
Physical Review C (Impact Factor: 3.73). 03/2008; 77(3). DOI: 10.1103/PhysRevC.77.034906

ABSTRACT Transverse momentum spectra up to 4.5 GeV/c around midrapidity of π±,p,p̅ , and K± in Pb+Pb reactions were measured at √sNN=17.3 GeV by the CERN-NA49 experiment. The nuclear modification factors RAA for π± and RCP for π±,p,p̅ ,K± were extracted and compared with results obtained at the BNL Relativistic Heavy Ion Collider (RHIC) at √sNN=200 GeV. The modification factor RAA shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor RCP, in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the π± channel. The extracted RCP values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for π± above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.

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