Hydrodynamics of charge fluctuations and balance functions

Abstract

We apply stochastic hydrodynamics to the study of charge density fluctuations in QCD matter undergoing Bjorken expansion. We find that the charge density correlations are given by a time integral over the history of the system, with the dominant contribution coming from the QCD crossover region where the change of susceptibility per entropy, chi T/s, is most significant. We study the rapidity and azimuthal angle dependence of the resulting charge balance function using a simple analytic model of heavy-ion collision evolution. Our results are in agreement with experimental measurements, indicating that hydrodynamic fluctuations contribute significantly to the measured charge correlations in high energy heavy-ion collisions. The sensitivity of the balance function to the value of the charge diffusion coefficient D allows us to estimate the typical value of this coefficient in the crossover region to be rather small, of the order of 1/(2pi T), characteristic of a strongly coupled plasma.

13 pages, 7 figures. Minor modifications in v2 which matches published version

References in corpus (9)

• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• The QCD equation of state with dynamical quarks
• The QCD Equation of State with almost Physical Quark Masses
• Equation of state and QCD transition at finite temperature
• Electrical conductivity of the quark-gluon plasma across the deconfinement transition
• Collision Energy Dependence of Viscous Hydrodynamic Flow in Relativistic Heavy-Ion Collisions
• Thermal Conductivity and Chiral Critical Point in Heavy Ion Collisions
• Beam-Energy and System-Size Dependence of Dynamical Net Charge Fluctuations
• Charge conservation and the shape of the ridge of two-particle correlations in relativistic heavy-ion collisions

Cited by in corpus (31)

• Fluctuations of conserved charges in relativistic heavy ion collisions: An introduction
• Acceptance dependence of fluctuation measures near the QCD critical point
• The QCD phase diagram and Beam Energy Scan physics: a theory overview
• Electrical conductivity of the quark-gluon plasma and soft photon spectrum in heavy-ion collisions
• Thermal Relaxation, Electrical Conductivity and Charge Diffusion in a Hot QCD Medium
• Effects of global charge conservation on time evolution of cumulants of conserved charges in relativistic heavy ion collisions
• Evolving Charge Correlations in a Hybrid Model with both Hydrodynamics and Hadronic Boltzmann Descriptions
• Fluid dynamic propagation of initial baryon number perturbations on a Bjorken flow background
• Causal Electric Charge Diffusion and Balance Functions in Relativistic Heavy Ion Collisions
• Axial Charge Fluctuation and Chiral Magnetic Effect from Stochastic Hydrodynamics
• Rapidity window dependences of higher order cumulants and diffusion master equation
• Rapidity Correlation Structure in Nuclear Collisions
• Dynamics of critical fluctuations: Theory -- phenomenology -- heavy-ion collisions
• Evolution of Charge Fluctuations and Correlations in the Hydrodynamic Stage of Heavy Ion Collisions
• Calculating Fluctuations and Self-Correlations Numerically for Causal Charge Diffusion in Relativistic Heavy-Ion Collisions
• The "ripples" on relativistically expanding fluid
• Anisotropic hydrodynamics with number-conserving kernels
• Toward a description of the centrality dependence of the charge balance function in the HYDJET++ model
• Charge Conservation and Higher Moments of Charge Fluctuations
• Relating Measurable Correlations in Heavy Ion Collisions to Bulk Properties of Equilibrated QCD Matter
• Calculating n-Point Charge Correlations in Evolving Systems
• Consistent Implementation of Finite-Range Terms into Hydrodynamics
• The BEST framework for the search for the QCD critical point and the chiral magnetic effect
• Density correlations under global and local charge conservation
• Thermal noise in non-boost-invariant dissipative hydrodynamics
• Effect of chiral imbalance on the electrical conductivity of hot and dense quark matter using Green-Kubo Method within the 2-flavour gauged NJL model
• Thermal fluctuations on the freeze-out surface of heavy-ion collisions and their impact on particle correlations
• Causal hydrodynamic fluctuations in a one-dimensional expanding system
• Dynamics of the conserved net-baryon density near QCD critical point within inhomogeneous quark-gluon plasma profile
• Conserved Charge Susceptibilities in a Chemically Frozen Hadronic Gas
• Balance functions of charged hadron pairs $(\pi ,K,p)\otimes (\pi ,K,p)$ in Pb--Pb collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}=$2.76 TeV