System Size, Energy, and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy-Ion Collisions
- Argonne National Laboratory, Argonne, Illinois 60439-4843 (United States)
- Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States)
We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, {radical}(s{sub NN})=22.4, 62.4, and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. A comparison of Cu+Cu and Au+Au results shows that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same N{sub part}/2A rather than the same N{sub part}. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.
- OSTI ID:
- 21180351
- Journal Information:
- Physical Review Letters, Vol. 102, Issue 14; Other Information: DOI: 10.1103/PhysRevLett.102.142301; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
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