Charged-hadron suppression in Pb plus Pb and Xe plus Xe collisions measured with the ATLAS detector

Authors：Balek Petr; 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; Alexopoulos T

Source：Nuclear Physics A, 2019, 982: 571-574.

DOI：10.1016/j.nuclphysa.2018.10.079

• xenon-xenon collisions
• lead-lead collisions
• charged-hadron production
• nuclear modification factor

The ATLAS detector at the LHC recorded 0.49 nb(-1) of Pb+Pb collisions and 25 of pp(-1) collisions, both at the center-of-mass energy 5.02 TeV per nucleon pair. Recently, ATLAS also recorded 30 mu b(-1) of Xe+Xe collisions at the center-of-mass energy 5.44 TeV, which provides a new opportunity to study the system-size dependence of the charged-hadron production in heavy-ion collisions. The large acceptance of the ATLAS detector allows to measure the spectra of charged hadrons in a wide range of pseudorapidity and transverse momentum. The nuclear modification factors R-AA are constructed as a ratio of the spectra measured in Pb+Pb or Xe+Xe collisions to that measured in pp collisions. The R-AA obtained in the two systems are presented for different centrality intervals and the results are discussed.

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