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Compact Muon Solenoid
LHC, CERN

CMS-PAS-HIN-21-017
Multiplicity and transverse momentum dependence of charge balance function in pPb and PbPb collisions
Abstract: We report the charge-dependent two-particle differential correlation function in PbPb at $\sqrt {\smash [b]{s_{_{\mathrm {NN}}}}}$ = 5.02 TeV and pPb collisions at $\sqrt {\smash [b]{s_{_{\mathrm {NN}}}}}$ = 8.16 TeV. The correlation function is used to study the charge creation mechanism in high-energy heavy-ion collisions. The charge balance function is constructed using the like- and unlike-charge pairs to quantify the correlation of the emitted particles, such as the development of the collectivity and time the charges are created. The multiplicity dependence of balance function is observed both in relative pseudorapidity ($\Delta \eta$) and relative azimuthal angle ($\Delta \varphi$). The charge-dependent study of the correlation function shows the width of the balance function decreases towards the high multiplicity collisions in the low transverse momentum region ($p_{\mathrm{T}} < $ 2 GeV/$c$) for both systems. Neither HYDJET nor HIJING can reproduce the multiplicity dependence, while AMPT is consistent with the experimental findings. No significant multiplicity dependency is observed at larger transverse momentum.
CMS Publications
Compact Muon Solenoid
LHC, CERN