scholarly journals Constraining the Chiral Magnetic Effect with charge-dependent azimuthal correlations in Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ = 2.76 and 5.02 TeV

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
A. Adler ◽  
J. Adolfsson ◽  
...  
Keyword(s):  
Charged Particles ◽  
Magnetic Effect ◽  
Anisotropic Flow ◽  
Charge Conservation ◽  
Particle Correlations ◽  
Azimuthal Correlations ◽  
Chiral Magnetic Effect ◽  
Local Charge ◽  
Peripheral Collisions ◽  
Dependent Signal

Abstract Systematic studies of charge-dependent two- and three-particle correlations in Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 2.76 and 5.02 TeV used to probe the Chiral Magnetic Effect (CME) are presented. These measurements are performed for charged particles in the pseudorapidity (η) and transverse momentum (pT) ranges |η| < 0.8 and 0.2 < pT< 5 GeV/c. A significant charge-dependent signal that becomes more pronounced for peripheral collisions is reported for the CME-sensitive correlators γ1, 1 = 〈cos(φα + φβ − 2Ψ2)〉 and γ1, − 3 = 〈cos(φα − 3φβ + 2Ψ2)〉. The results are used to estimate the contribution of background effects, associated with local charge conservation coupled to anisotropic flow modulations, to measurements of the CME. A blast-wave parametrisation that incorporates local charge conservation tuned to reproduce the centrality dependent background effects is not able to fully describe the measured γ1,1. Finally, the charge and centrality dependence of mixed-harmonics three-particle correlations, of the form γ1, 2 = 〈cos(φα + 2φβ − 3Ψ3)〉, which are insensitive to the CME signal, verify again that background contributions dominate the measurement of γ1,1.

scholarly journals CHIRAL MAGNETIC EFFECT AND QCD PHASE TRANSITIONS WITH EFFECTIVE MODELS

2011 ◽  
Vol 26 (25) ◽  
pp. 4335-4365 ◽  
Author(s):  
WEI-JIE FU ◽  
YU-XIN LIU ◽  
YUE-LIANG WU
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Charged Particle ◽  
Electric Current ◽  
Current Density ◽  
Magnetic Effect ◽  
Chiral Phase ◽  
Particle Correlations ◽  
Chiral Magnetic Effect ◽  
Total Multiplicity

We study the influence of the chiral phase transition on the chiral magnetic effect. The chiral electric current density along the magnetic field, the electric charge difference between on each side of the reaction plane, and the azimuthal charged-particle correlations as functions of the temperature during the QCD phase transitions are calculated. It is found that with the decrease of the temperature, the chiral electric current density, the electric charge difference, and the azimuthal charged-particle correlations all get a sudden suppression at the critical temperature of the chiral phase transition, because the large quark constituent mass in the chiral symmetry broken phase quite suppresses the axial anomaly and the chiral magnetic effect. We suggest that the azimuthal charged-particle correlations (including the correlators divided by the total multiplicity of produced charged particles which are used in current experiments and another kind of correlators not divided by the total multiplicity) can be employed to identify the occurrence of the QCD phase transitions in RHIC energy scan experiments.

scholarly journals Observation of Charge-Dependent Azimuthal Correlations in p−Pb Collisions and Its Implication for the Search for the Chiral Magnetic Effect

2017 ◽  
Vol 118 (12) ◽  
Author(s):  
V. Khachatryan ◽  
A. M. Sirunyan ◽  
A. Tumasyan ◽  
W. Adam ◽  
E. Asilar ◽  
...  
Keyword(s):  
Magnetic Effect ◽  
Azimuthal Correlations ◽  
Chiral Magnetic Effect

scholarly journals Systematic study of the chiral magnetic effect with the AVFD model at LHC energies

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Panos Christakoglou ◽  
Shi Qiu ◽  
Joey Staa
Keyword(s):  
Fluid Dynamics ◽  
Viscous Fluid ◽  
Systematic Study ◽  
Quantitative Description ◽  
Axial Current ◽  
Magnetic Effect ◽  
The Other ◽  
Experimental Measurements ◽  
Chiral Magnetic Effect ◽  
Local Charge

AbstractWe present a systematic study of the correlators used experimentally to probe the Chiral Magnetic Effect (CME) using the Anomalous Viscous Fluid Dynamics (AVFD) model in Pb–Pb and Xe–Xe collisions at LHC energies. We find a parametrization that describes the dependence of these correlators on the value of the axial current density ($$n_5/{\mathrm {s}}$$ n 5 / s ), which dictates the CME signal, and on the parameter that governs the background in these measurements i.e., the percentage of local charge conservation (LCC) within an event. This allows to deduce the values of $$n_5/{\mathrm {s}}$$ n 5 / s and the LCC percentage that provide a quantitative description of the centrality dependence of the experimental measurements. We find that the results in Xe–Xe collisions at $$\sqrt{s_{\mathrm {NN}}} = 5.44$$ s NN = 5.44  TeV are consistent with a background only scenario. On the other hand, the model needs a significant non-zero value of $$n_5/{\mathrm {s}}$$ n 5 / s to match the measurements in Pb–Pb collisions at $$\sqrt{s_{\mathrm {NN}}} = 5.02$$ s NN = 5.02  TeV.

scholarly journals New experimental constrains on chiral magnetic effect using charge-dependent azimuthal correlation in pPb and PbPb collisions at the LHC

2018 ◽  
Vol 172 ◽  
pp. 01004 ◽  
Author(s):  
Zhoudunming Tu
Keyword(s):  
Heavy Ion ◽  
Magnetic Effect ◽  
Azimuthal Anisotropy ◽  
Event Shape ◽  
Azimuthal Correlations ◽  
Ion Collisions ◽  
Chiral Magnetic Effect ◽  
Cms Experiment ◽  
Engineering Technique ◽  
Particle Pairs

Studies of charge-dependent azimuthal correlations for the same- and oppositesign particle pairs are presented in PbPb collisions at 5 TeV and pPb collisions at 5 and 8.16 TeV, with the CMS experiment at the LHC. The azimuthal correlations are evaluated with respect to the second- and also higher-order event planes, as a function of particle pseudorapidity and transverse momentum, and event multiplicity. By employing an event-shape engineering technique, the dependence of correlations on azimuthal anisotropy flow is investigated. Results presented provide new insights to the origin of observed charge-dependent azimuthal correlations, and have important implications to the search for the chiral magnetic effect in heavy ion collisions.

scholarly journals Particle correlations and the chiral magnetic effect

2016 ◽  
Vol 52 (8) ◽  
Author(s):  
Adam Bzdak ◽  
Volker Koch ◽  
Jinfeng Liao
Keyword(s):  
Magnetic Effect ◽  
Particle Correlations ◽  
Chiral Magnetic Effect

scholarly journals Non-Hermitian Chiral Magnetic Effect in Equilibrium

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 761 ◽  
Author(s):  
Maxim N. Chernodub ◽  
Alberto Cortijo
Keyword(s):  
Quantum Mechanics ◽  
Thermodynamic Limit ◽  
Magnetic Effect ◽  
Charge Conservation ◽  
Bloch Theorem ◽  
Chiral Magnetic Effect ◽  
Fermionic Systems

We analyze the chiral magnetic effect for non-Hermitian fermionic systems using the bi-orthogonal formulation of quantum mechanics. In contrast to the Hermitian counterparts, we show that the chiral magnetic effect takes place in equilibrium when a non-Hermitian system is considered. The key observation is that for non-Hermitian charged systems, there is no strict charge conservation as understood in Hermitian systems, so the Bloch theorem preventing currents in the thermodynamic limit and in equilibrium does not apply.

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