Abstract
Measurements of the midrapidity transverse-energy distribution, dET/dη, are presented for p+p, d+Au, and Au+Au collisions at sNN=200 GeV and additionally for Au+Au collisions at sNN=62.4 and 130 GeV. The dET/dη distributions are first compared with the number of nucleon participants Npart, number of binary collisions Ncoll, and number of constituent-quark participants Nqp calculated from a Glauber model based on the nuclear geometry. For Au+Au, dET/d/Npart increases with Npart, while dET/d/Nqp is approximately constant for all three energies. This indicates that the two-component ansatz, dET/d (1-x)Npart/2+xNcoll, which was used to represent ET distributions, is simply a proxy for Nqp, and that the Ncoll term does not represent a hard-scattering component in ET distributions. The dET/dη distributions of Au+Au and d+Au are then calculated from the measured p+p ET distribution using two models that both reproduce the Au+Au data. However, while the number-of-constituent-quark- participant model agrees well with the d+Au data, the additive-quark model does not.
Original language | English |
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Article number | 044905 |
Journal | Physical Review C |
Volume | 89 |
Issue number | 4 |
DOIs | |
State | Published - 9 Apr 2014 |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics