Pseudorapidity and centrality dependence of the collective flow of charged particles in Au+Au collisions at sqrt[s(NN)]=130 GeV.

ABSTRACT

This paper describes the measurement of collective flow for charged particles in Au+Au collisions at sqrt[s(NN)]=130 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider (RHIC). The measured azimuthal hit anisotropy is presented over a wide range of pseudorapidity (-5.0time at this energy. The result, averaged over momenta and particle species, is observed to reach 7% for peripheral collisions at midrapidity, falling off with centrality and increasing |eta|. These results call into question the common assumption of longitudinal boost invariance over a large region of rapidity in RHIC collisions.