Forward-rapidity azimuthal and radial flow of identified particles for Au+Au collisions

A strong azimuthal flow signature at RHIC suggests rapid system equilibration leading to an almost perfect fluid state. The longitudinal extent of the flow behavior depends on how this state is formed and can be studied by measuring the pseudorapidity and transverse momentum dependence of the second Fourier component (ν2(pT)) of the azimuthal angular distribution. We report on a measurement of identified-particle ν2 as a function of pT(0.5−2.0GeV/c), centrality (0-25%, 25-50%), and pseudorapidity (0⩽η<3.2) for Au+Au collisions. The BRAHMS spectrometers are used for particle identification (π, K, p) and momentum determination and the BRAHMS global detectors are used to determine the corresponding reaction-plane angles. The results are discussed in terms of the pseudorapidity dependence of constituent quark scaling and in terms of models that develop the complete (azimuthal and radial) hydrodynamic aspects of the forward dynamics at RHIC.