Abstract
The centrality dependence of transverse momentum distributions and yields for π±,K±, p, and p in Au +Au collisions at √sNN=200 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider. We observe a clear particle mass dependence of the shapes of transverse momentum spectra in central collisions below ∼2 GeV/c in pT. Both mean transverse momenta and particle yields per participant pair increase from peripheral to midcentral and saturate at the most central collisions for all particle species. We also measure particle ratios of π-/π+, K -/K+, ̄p/p, K/π, p/π, and ̄p/π as a function of pT and collision centrality. The ratios of equal mass particle yields are independent of pT and centrality within the experimental uncertainties. In central collisions at intermediate transverse momenta ∼1.5-4.5 GeV/c, proton and antiproton yields constitute a significant fraction of the charged hadron production and show a scaling behavior different from that of pions.
Original language | English |
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Article number | 034909 |
Pages (from-to) | 034909-1-034909-32 |
Journal | Physical Review C - Nuclear Physics |
Volume | 69 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2004 |
Funding
We thank the staff of the Collider-Accelerator and Physics Departments at Brookhaven National Laboratory and the staff of the other PHENIX participating institutions for their vital contributions. We acknowledge support from the Department of Energy, Office of Science, Nuclear Physics Division, the National Science Foundation, Abilene Christian University Research Council, Research Foundation of SUNY, and Dean of the College of Arts and Sciences, Vanderbilt University (USA), Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan), Conselho Nacional de Desenvolvimento Científico e Tecnológico and Fundação de Amparo à Pesquisa do Estado de São Paulo (Brazil), Natural Science Foundation of China (People’s Republic of China), Centre National de la Recherche Scientifique, Commissariat à l’Énergie Atomique, Institut National de Physique Nucléaire et de Physique des Particules, and Institut National de Physique Nucléaire et de Physique des Particules (France), Bundesministerium fuer Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany), Hungarian National Science Fund, OTKA (Hungary), Department of Atomic Energy and Department of Science and Technology (India), Israel Science Foundation (Israel), Korea Research Foundation and Center for High Energy Physics (Korea), Russian Ministry of Industry, Science and Tekhnologies, Russian Academy of Science, Russian Ministry of Atomic Energy (Russia), VR and the Wallenberg Foundation (Sweden), the U.S. Civilian Research and Development Foundation for the Independent States of the Former Soviet Union, the US-Hungarian NSF-OTKA-MTA, the US-Israel Binational Science Foundation, and the Fifth European Union TMR Marie-Curie Programme.