Universal scaling of the elliptic flow data at RHIC
  Recent PHOBOS measurements of the excitation function for the pseudo-rapidity dependence of elliptic flow in Au+Au collisions at RHIC, have posed a significant theoretical challenge. Here we show that these differential measurements, as well as the RHIC measurements on transverse momentum satisfy a universal scaling relation predicted by the Buda-Lund model, based on exact solutions of perfect fluid hydrodynamics. We also show that recently found transverse kinetic energy scaling of the elliptic flow is a special case of this universal scaling. 
M. Csanad, T. Csorgo, A. Ster, B. Lorstad, N. N. Ajitanand, J. M.   Alexander, P. Chung, W. G. Holzmann, M. Issah, R. A. Lacey