Abstract
Forward calorimetry in the PHOBOS detector has been used to study charged hadron production in , and collisions at . The forward proton calorimeter detectors are described and a procedure for determining collision centrality with these detectors is detailed. The deposition of energy by deuteron spectator nucleons in the forward calorimeters is used to identify and collisions in the data. A weighted combination of the yield of and is constructed to build a reference for collisions that better matches the isospin composition of the gold nucleus. The and centrality dependence of the yield of this improved reference system is found to match that of . The shape of the charged-particle transverse momentum distribution is observed to extrapolate smoothly from to central as a function of the charged-particle pseudorapidity density. The asymmetry of positively and negatively charged hadron production in is compared to that of . No significant asymmetry is observed at midrapidity. These studies augment recent results from experiments at the CERN Large Hadron Collider and BNL Relativistic Heavy Ion Collider facilities to give a more complete description of particle production in and collisions, essential for the understanding the medium produced in high-energy nucleus-nucleus collisions.
11 More- Received 25 May 2015
DOI:https://doi.org/10.1103/PhysRevC.92.034915
©2015 American Physical Society