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Title: 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
A bstract 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 ( p T ) ranges | η | < 0 . 8 and 0 . 2 < p T < 5 GeV/ c . A significant charge-dependent signal that becomes more pronounced for peripheral collisions is reported for the CME-sensitive correlators γ 1, 1  = 〈cos( φ α  +  φ β  − 2Ψ 2 )〉 and γ 1, − 3  = 〈cos( φ α  − 3 φ β  + 2Ψ 2 )〉. 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 γ 1 , 1 . Finally, the charge and centrality dependence of mixed-harmonics three-particle correlations, of the form γ 1, 2  = 〈cos( φ α  + 2 φ β  − 3Ψ 3 )〉, which are insensitive to the more » CME signal, verify again that background contributions dominate the measurement of γ 1 , 1 . « less
Authors:
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Award ID(s):
1719759 2012154 1713894
Publication Date:
NSF-PAR ID:
10278021
Journal Name:
Journal of High Energy Physics
Volume:
2020
Issue:
9
ISSN:
1029-8479
Sponsoring Org:
National Science Foundation
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