Elliptic flow in Au plus Au collisions at root s(NN)=130 GeV

摘要

We report the elliptic flow of charged and identified particles at mid-rapidity in Au+Au collisions at roots(NN) = 130 GeV using the STAR TPC at RHIC. The integrated elliptic flow signal, v(2), for charged particles reaches values of about 0.06, indicating a higher degree of thermalization than at lower energies. The differential elliptic flow signal, v(2)(p(t)) up to 1.5 GeV/c, shows a behavior expected from hydrodynamic model calculations. Above 1.5 GeV/c, the data deviate from the hydro predictions; however the v(2)(pt) is still large, suggesting finite asymmetry for the products of hard scattering. For the identified particles, elliptic flow as a function of pt and centrality differ significantly for particles of different masses. This dependence can be accounted for in hydrodynamic models, indicating that the system created shows a behavior consistent with collective hydrodynamical flow. [References: 20]