Description of η-distributions at RHIC energies in terms of a stochastic model

To explain \eta-distributions at RHIC energies we consider the Ornstein-Uhlenbeck process. To account for hadrons produced in the central region, we assume existence of third source located there (y \approx 0) in addition to two sources located at the beam and target rapidities (\pm y_{max} = \pm \ln[\sqrt{s_{NN}}/m_{N}]). This results in better \chi^2/n.d.f. than those for only two sources when analysing data.