Rapidity Correlation Structures from Causal Hydrodynamics

Sean Gavin,George Moschelli,Christopher Zin

doi:10.1088/1742-6596/736/1/012020

Sean Gavin, George Moschelli + Show 1 more

Open Access

https://doi.org/10.1088/1742-6596/736/1/012020

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Abstract

Viscous diffusion can broaden the rapidity dependence of two-particle transverse momentum fluctuations. Surprisingly, measurements at RHIC by the STAR collaboration demonstrate that this broadening is accompanied by the appearance of unanticipated structure in the rapidity distribution of these fluctuations in the most central collisions. Although a first order classical Navier-Stokes theory can roughly explain the rapidity broadening, it cannot explain the additional structure. We propose that the rapidity structure can be explained using the second order causal Israel-Stewart hydrodynamics with stochastic noise.

Highlights

Many experimental measurements demonstrate the profound effect that initial state fluctuations of nuclear collisions have on the subsequent dynamics of the system, but there is growing awareness that fluctuations and their dissipation occur throughout the evolution
In earlier work we suggested that viscous diffusion broadens the rapidity dependence of two-particle transverse momentum correlations [1]
We discuss how the diffusion equation derived from second order hydrodynamics, (6), modifies this result

Summary

Introduction

Many experimental measurements demonstrate the profound effect that initial state fluctuations of nuclear collisions have on the subsequent dynamics of the system, but there is growing awareness that fluctuations and their dissipation occur throughout the evolution. In earlier work we suggested that viscous diffusion broadens the rapidity dependence of two-particle transverse momentum correlations [1]. In this work we will compare rapidity correlation structures evolving from first and second order diffusion.

Results

Conclusion