\eta-Scaling of dN_{ch}/d\eta at sqrt{s_{NN}} = 200 GeV by the PHOBOS   Collaboration and the Ornstein-Uhlenbeck stochastic process
  Using the latest data concerning $dN_{\rm ch}/d\eta$ at $\sqrt{s_{NN}} = 200$ GeV, we have analyzed them by means of stochastic theory named the Ornstein-Uhlenbeck process with two sources. Moreover, we display that $z_r = \eta/\sqrt{< \eta^2>} = \eta/\eta_{rms}$ scaling with centrality cuts are described by two Gaussian distributions. 
Minoru Biyajima and Takuya Mizoguchi