Probing the Color Structure of the Perfect QCD Fluids via Soft-Hard-Event-by-Event Azimuthal Correlations

We develop a comprehensive dynamical framework, CIBJET, to calculate on an event-by-event basis the dependence of correlations between soft ($p_T<2$ Gev) and hard ($p_T> 10$ Gev) azimuthal flow angle harmonics on the color composition of near-perfect QCD fluids produced in high energy nuclear collisions at RHIC and LHC. CIBJET combines consistently predictions of event-by-event VISHNU2+1 viscous hydrodynamic fluid fields with CUJET3.1 predictions of event-by-event jet quenching. We find that recent correlation data favor a temperature dependent color composition including bleached chromo-electric $q(T)+g(T)$ components and an emergent chromo-magnetic degrees of freedom $m(T)$ consistent with non-perturbative lattice QCD information in the confinement/deconfinement temperature range.Comment: 6 pages, 6 figures; Accepted version to appear in Chinese Physics

Anomalous Chiral Transport in Heavy Ion Collisions from Anomalous-Viscous Fluid Dynamics

Chiral anomaly is a fundamental aspect of quantum theories with chiral fermions. How such microscopic anomaly manifests itself in a macroscopic many-body system with chiral fermions, is a highly nontrivial question that has recently attracted significant interest. As it turns out, unusual transport currents can be induced by chiral anomaly under suitable conditions in such systems, with the notable example of the Chiral Magnetic Effect (CME) where a vector current (e.g. electric current) is generated along an external magnetic field. A lot of efforts have been made to search for CME in heavy ion collisions, by measuring the charge separation effect induced by the CME transport. A crucial challenge in such effort, is the quantitative prediction for the CME signal. In this paper, we develop the Anomalous-Viscous Fluid Dynamics (AVFD) framework, which implements the anomalous fluid dynamics to describe the evolution of fermion currents in QGP, on top of the neutral bulk background described by the VISH2+1 hydrodynamic simulations for heavy ion collisions. With this new tool, we quantitatively and systematically investigate the dependence of the CME signal to a series of theoretical inputs and associated uncertainties. With realistic estimates of initial conditions and magnetic field lifetime, the predicted CME signal is quantitatively consistent with measured change separation data in 200GeV Au-Au collisions. Based on analysis of Au-Au collisions, we further make predictions for the CME observable to be measured in the planned isobaric (Ru-Ru v.s. Zr-Zr ) collision experiment, which could provide a most decisive test of the CME in heavy ion collisions.Comment: 28 pages, 13 figures; published versio

Quantification of Chiral Magnetic Effect from Event-by-Event Anomalous-Viscous Fluid Mechanics

Chiral Magnetic Effect (CME) is the macroscopic manifestation of the fundamental chiral anomaly in a many-body system of chiral fermions, and emerges as anomalous transport current in hydrodynamic framework. Experimental observation of CME is of great interest and significant efforts have been made to look for its signals in heavy ion collisions. Encouraging evidence of CME-induced charge separation has been reported from both RHIC and LHC, albeit with ambiguity due to potential background contributions. Crucial for addressing such issue, is the need of quantitative predictions for both CME signal and the non-CME background consistently, with sophisticated modeling tool. In this contribution we report a recently developed Anomalous Viscous Fluid Dynamics (AVFD) framework, which simulates the evolution of fermion currents in QGP on top of the data-validated VISHNU bulk hydro evolution. In particular, this framework has been extended to event-by-event simulations with proper implementation of known flow-driven background contributions. We report quantitative results from such simulations and evaluate the implications for interpretations of current experimental measurements. Finally we give our prediction for the CME signal in upcoming isobaric collisions.Comment: 5 pages, 7 figures; plenary talk at CPOD 2017 conference, Stony Brook University, Stony Brook, NY. arXiv admin note: substantial text overlap with arXiv:1704.05531; text overlap with arXiv:1611.0458