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

作者：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

来源：Nuclear Physics A, 2019, 982: 479-482.

DOI：10.1016/j.nuclphysa.2018.09.076

• QGP
• heavy ion collisions
• small systems
• collectivity
• symmetric cumulants
• subevent cumulants

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.

• 单位
  香港科技大学; 香港理工大学; 南京大学; 香港中文大学; 中国地震局; 中国科学院; 上海交通大学; 清华大学; 山东大学; 空; 香港大学