Transverse-Momentum Spectra in Au+Au and d+Au Collisions at (sNN)=200 GeV and the Pseudorapidity Dependence of High-pT Suppression
Abstract
We present spectra of charged hadrons from Au+Au and d+Au collisions at (sNN)=200 GeV measured with the BRAHMS experiment at RHIC. The spectra for different collision centralities are compared to spectra from p+p¯ collisions at the same energy scaled by the number of binary collisions. The resulting ratios (nuclear modification factors) for central Au+Au collisions at η=0 and η=2.2 evidence a strong suppression in the high pT region (>2 GeV/c). In contrast, the d+Au nuclear modification factor (at η=0) exhibits an enhancement of the high pT yields. These measurements indicate a high energy loss of the high pT particles in the medium created in the central Au+Au collisions. The lack of suppression in d+Au collisions makes it unlikely that initial state effects can explain the suppression in the central Au+Au collisions.
- Publication:
-
Physical Review Letters
- Pub Date:
- August 2003
- DOI:
- 10.1103/PhysRevLett.91.072305
- arXiv:
- arXiv:nucl-ex/0307003
- Bibcode:
- 2003PhRvL..91g2305A
- Keywords:
-
- 25.75.Dw;
- Particle and resonance production;
- Nuclear Experiment
- E-Print:
- 4 pages, 4 figures, submitted to Phys. Rev. Lett