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Title: Importance of non-flow in mixed-harmonic multi-particle correlations in small collision systems

Journal Article · · Physics Letters. B
 [1];  [2]; ORCiD logo [3]; ORCiD logo [2]
  1. Stony Brook Univ., Stony Brook, NY (United States)
  2. Univ. of Copenhagen, Copenhagen (Denmark)
  3. Stony Brook Univ., Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

Recently CMS Collaboration measured mixed-harmonic four-particle azimuthal correlations, known as symmetric cumulants SC(n, m), in pp and p+Pb collisions, and interpreted the non-zero SC(n, m) as evidence for long-range collectivity in these small collision systems. Using the PYTHIA and HIJING models which do not have genuine long-range collectivity, we show that the CMS results, obtained with standard cumulant method, could be dominated by non-flow effects associated with jet and dijets, especially in pp collisions. We show that the non-flow effects are largely suppressed using the recently proposed subevent cumulant methods by requiring azimuthal correlation between two or more pseudorapidity ranges. As a result, we argue that the reanalysis of SC(n, m) using the subevent method in experiments is necessary before they can used to provide further evidences for a long-range multi-particle collectivity and constraints on theoretical models in small collision systems.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP)
Grant/Contract Number:
SC0012704
OSTI ID:
1439313
Report Number(s):
BNL-205708-2018-JAAM; TRN: US1900601
Journal Information:
Physics Letters. B, Vol. 777, Issue C; ISSN 0370-2693
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 30 works
Citation information provided by
Web of Science

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Cited By (8)

Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in $pp$, $p-Pb$, Xe-Xe, and Pb-Pb Collisions at the LHC text January 2019
Centrality fluctuations in heavy-ion collisions text January 2018
Anisotropic flow in Xe-Xe collisions at $\mathbf{\sqrt{s_{\rm{NN}}} = 5.44}$ TeV text January 2018
Correlated long-range mixed-harmonic fluctuations measured in $pp$, $p$+Pb and low-multiplicity Pb+Pb collisions with the ATLAS detector text January 2018
Investigations of anisotropic flow using multi-particle azimuthal correlations in pp, p-Pb, Xe-Xe, and Pb-Pb collisions at the LHC text January 2019
Correlations of azimuthal anisotropy Fourier harmonics with subevent cumulants in pPb collisions at $\sqrt{s_\mathrm{NN}} =$ 8.16 TeV text January 2019
Hadronic Rescattering in pA and AA Collisions text January 2021
Correlations of azimuthal anisotropy Fourier harmonics with subevent cumulants in pPb collisions at √$^{S}$NN = 8.16 TeV text January 2021

Figures / Tables (6)