Hydrodynamical noise and Gubser flow

TL;DR

This paper investigates the impact of hydrodynamical noise on Gubser flow in ultra-central collision events at the LHC, revealing its effects on flow anisotropies and correlation structures across different collision systems.

Contribution

It introduces hydrodynamical noise into Gubser's analytical solution and analyzes its effects on flow harmonics and correlations in high-energy collisions.

Findings

Hydrodynamical noise amplitude depends on collision multiplicity.

Hydrodynamical noise slightly enhances azimuthal anisotropies, especially in p-p systems.

Hydrodynamical noise contributes to near-side peak formation in short-range correlations.

Abstract

Hydrodynamical noise is introduced on top of Gubser's analytical solution to viscous hydrodynamics. With respect to the ultra-central collision events of Pb-Pb, p-Pb and p-p at the LHC energies, we solve the evolution of noisy fluid systems and calculate the radial flow velocity correlations. We show that the absolute amplitude of the hydrodynamical noise is determined by the multiplicity of the collision event. The evolution of azimuthal anisotropies, which is related to the generation of harmonic flow, receives finite enhancements from hydrodynamical noise. Although it is strongest in the p-p systems, the effect of hydrodynamical noise on flow harmonics is found to be negligible, especially in the ultra-central Pb-Pb collisions. For the short-range correlations, hydrodynamical noise contributes to the formation of a near-side peak on top of the correlation structure originated from initial state fluctuations. The shape of the peak is affected by the strength of hydrodynamical noise, whose height and width grow from the Pb-Pb system to the p-Pb and p-p systems.