Beam Energy Dependence of Rapidity Correlation Structure in Nuclear Collisions

Viscous diffusion can broaden the rapidity dependence of two-particle transverse momentum fluctuations. Furthermore, detailed changes in the rapidity dependence of these correlations can be used to determine the characteristic time $\tau_\pi$ for the rate of isotropization of the stress energy tensor. Measurements at the top RHIC energy by the STAR collaboration exhibit a rapidity distribution roughly consistent with $\tau_\pi/\nu \sim 10$ [1]. We extend the second order dissipative hydrodynamics with noise of ref. 1 to include a realistic equation of state and temperature dependent transport coefficients. Our computations are used to predict the energy dependence of the rapidity distribution.