Experimental searches for the chiral magnetic effect in heavy-ion collisions

Abstract

The chiral magnetic effect (CME) in quantum chromodynamics (QCD) refers to a charge separation (an electric current) of chirality imbalanced quarks generated along an external strong magnetic field. The chirality imbalance results from interactions of quarks, under the approximate chiral symmetry restoration, with metastable local domains of gluon fields of non-zero topological charges out of QCD vacuum fluctuations. Those local domains violate the $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ invariance, potentially offering a solution to the strong $\mathcal{C}\mathcal{P}$ problem in explaining the magnitude of the matter-antimatter asymmetry in today's universe. Relativistic heavy-ion collisions, with the likely creation of the high energy density quark-gluon plasma and restoration of the approximate chiral symmetry, and the possibly long-lived strong magnetic field, provide a unique opportunity to detect the CME. Early measurements of the CME-induced charge separation in heavy-ion collisions are dominated by physics backgrounds. Major efforts have been devoted to eliminate or reduce those backgrounds. We review those efforts, with a somewhat historical perspective, and focus on the recent innovative experimental undertakings in the search for the CME in heavy-ion collisions.

Invited review by Progress in Particle and Nuclear Physics, 57 pages, 33 figures

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Cited by in corpus (33)

• Properties of the QCD Matter -- An Experimental Review of Selected Results from RHIC BES Program
• Chiral magnetic effect reveals the topology of gauge fields in heavy-ion collisions
• Exploring QCD matter in extreme conditions with Machine Learning
• Strong-Field Physics in QED and QCD: From Fundamentals to Applications
• Chiral Magnetic Effect in Heavy Ion Collisions: The Present and Future
• Kinetic theory with spin: From massive to massless fermions
• Deconfinement and chiral phase transitions in quark matter with a strong electric field
• Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions
• Charge diffusion in relativistic resistive second-order dissipative magnetohydrodynamics
• Anomalous magnetohydrodynamics with temperature-dependent electric conductivity and application to the global polarization
• Global constraint on the magnitude of anomalous chiral effects in heavy-ion collisions
• Relativistic resistive magneto-hydrodynamics code for high-energy heavy-ion collisions
• Systematic study of the Chiral Magnetic Effect with the AVFD model at LHC energies
• Causality violation and the speed of sound of hot and dense quark matter in the Nambu--Jona-Lasinio model
• Photoproduction of $e^{+}{e}^{-}$ in peripheral isobar collisions
• Quantum version of transport coefficients in Nambu--Jona-Lasinio model at finite temperature and strong magnetic field
• Charge asymmetry dependence of flow and a novel correlator to detect the chiral magnetic wave in a multiphase transport model
• Review of nonflow estimation methods and uncertainties in relativistic heavy-ion collisions
• Collective dynamics of polarized spin-half fermions in relativistic heavy-ion collisions
• Magnetic field effects in peripheral heavy-ion collisions around 1 GeV/nucleon
• Shear viscosity coefficient of magnetized QCD medium near chiral phase transition
• Collective Excitation in High-Energy Nuclear Collisions -- In Memory of Professor Lianshou Liu
• Difference between signal and background of the chiral magnetic effect relative to spectator and participant planes in isobar collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}=200$ GeV
• Event-by-event correlations between $\Lambda$ ($\bar{\Lambda }$) hyperon global polarization and handedness with charged hadron azimuthal separation in Au+Au collisions at $\sqrt{s_{\text{NN}}}=27\text{ GeV}$ from STAR
• Chirality imbalance and chiral magnetic effect under a parallel electromagnetic field
• Chiral anomaly in a (1+1)-dimensional Floquet system under high-frequency electric fields
• Experimental review on the chiral magnetic effect in relativistic heavy ion collisions
• Influence of the chiral magnetic effect on particle-pair elliptic anisotropy
• Investigating event-shape methods in the search for the chiral magnetic effect in relativistic heavy ion collisions
• Magnetic helicity in plasma of chiral fermions electroweakly interacting with inhomogeneous matter
• Optimal Observables for the Chiral Magnetic Effect from Machine Learning
• Magnetic helicity in rotating neutron stars
• Helicity conservation in perfect electromagnetic and chiral fluids