Hydrodynamic Short-Range Correlations from Boltzmann-Langevin Equation

TL;DR

Short-range two-particle correlations in heavy-ion collisions can harbor hydrodynamic contributions from late-time fluctuations. The work uses the Boltzmann-Langevin framework to derive the equal-time two-point correlator and its dissipative corrections in both the relaxation-time approximation and a scalar theory with 2-to-2 scatterings. It provides a deterministic transport equation for the correlator, decomposes the first-order correction into singular (local) and regular (non-local) parts, and reveals a non-local hydrodynamic signature through a Legendre-expanded angular structure tied to transport coefficients. The findings propose a distinct hydrodynamic signal in short-range correlations that can be tested with high-precision measurements at RHIC and LHC.

Abstract

We investigate hydrodynamic contributions to short-range two-particle correlations in relativistic heavy-ion collisions using the Boltzmann-Langevin equation. We derive and solve the transport equation for equal-time two-point correlations, obtaining both local and non-local contributions that scale with transport coefficients. The non-local correlations emerging from 2-to-2 scattering dynamics provide a hydrodynamic signature in short-range correlation measurements.

Figures (1)

• Figure 1: Numerical solution of the two-point correlation function, with the relative angle $\theta_{pq}$ chosen with respect to the effective gap of pseudo-rapidity $\Delta\eta$.