Measurement of the flow harmonic correlations in pp, p plus Pb and low multiplicity Pb plus Pb collisions with the ATLAS detector at the LHC

Authors:Derendarz Dominik; Aaboud M; Aad G; Abbott B; Abdinov O; Abeloos B; Abhayasinghe D K; Abidi S H; AbouZeid O S; Abraham N L; Abramowicz H; Abreu H; Abulaiti Y; Acharya B S; Adachi S; Adam L; Adamczyk L; Adelman J; Adersberger M; Adiguzel A; Adye T; Affolder A A; Afik Y; Agheorghiesei C; Aguilar Saavedra J A; Ahmadov F; Aielli G; Akatsuka S; Akesson T P A; Akilli E; Akimov A V; Alberghi G L; Albert J; Albicocco P; Alconada Verzini M J; Alderweireldt S; Aleksa M; Aleksandrov I N; Alexa C
Source:Nuclear Physics A, 2019, 982: 479-482.
DOI:10.1016/j.nuclphysa.2018.09.076

Summary

Recent measurements of the correlations between flow harmonics obtained using four-particle symmetric cumulants and three-particle asymmetric cumulants with the ATLAS detector at the LHC are described. The data sets of pp, p+Pb and peripheral Pb+Pb collisions at various energies are analyzed, aiming to probe the long-range collective nature of multi-particle production in small systems. The sensitivity of the standard cumulant method to non-flow correlations is investigated by introducing the subevents method. A systematic reduction of non-flow effects is observed when using the two-subevent method. Further reduction is observed with the three-subevent method that is consistent with the results obtained with the four-subevent one. A negative correlation between v(2) and v(3) and a positive correlation between v(2) and v(4), for all studied collision systems and over full multiplicity range, is observed. The correlation strength computed as symmetric cumulants normalized by the < v(n)(2)> is similar for all collision systems and weakly depends on multiplicity. These measurements provide new evidence for long-range multi-particle collectivity in small collision systems and quantify the nature of its event-by-event fluctuations.

  • Institution
    Hong Kong University of Science & Technology; Hong Kong Polytechnic University; Nanjing University; Chinese University of Hong Kong; China Earthquake Administration; Chinese Academy of Science; Shanghai Jiao Tong University; Tsinghua University; Shandong University; 空

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