Hydrodynamics of charge fluctuations and balance functions
B. Ling
T. Springer
M. Stephanov
10027/20048
https://indigo.uic.edu/articles/Hydrodynamics_of_charge_fluctuations_and_balance_functions/10774478
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, χT /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 (2πT )
−1, characteristic of a strongly coupled
plasma
2016-01-27 00:00:00
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