ÚTEFČVUT Ústav technické a experimentální fyziky ČVUT v PrazeInstitute of Experimental and Applied Physics, CTU in Prague

Flow fluctuations in Pb plus Pb collisions at root s(NN)=5.02 TeV with the ATLAS detector

NázevTitle
Flow fluctuations in Pb plus Pb collisions at root s(NN)=5.02 TeV with the ATLAS detectorFlow fluctuations in Pb plus Pb collisions at root s(NN)=5.02 TeV with the ATLAS detector
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
M. Zhou, M. Aaboud, G. Aad, B. Abbott, B. Ali, K. Augsten, D. Caforio, P. Gallus, M. Havránek, Z. Hubáček, M. Myška, R. Novotný, T. Slavíček, K. Smolek, M. Solar, A. Sopczak, M. Suk, V. Vacek, P. Vokáč, V. Vrba
KonferenceConference
27th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (2018-05-14)
ExperimentCollaboration
ATLAS
DOIDOI
10.1016/j.nuclphysa.2018.09.012
Časopis / citaceJournal / citation
Nuclear Physics A 982, 323-326 (2019) · ISSN 0375-9474
RokYear
2019
JazykLanguage
eng
ZáznamyRecords
ProjektProject
Získávání nových poznatků o mikrosvětě v infrastruktuře CERNAcquiring new pieces of knowledge about micro-world in CERN research infrastructure
Plný text (open access)Full text (open access)
https://www.sciencedirect.com/science/article/pii/S0375947418302008/pdf
Citace ke staženíDownload citation
TXT · BibTeX

AbstraktAbstract

Measurements of four-particle cumulants c(n){4} for n = 1, 2, 3, 4 are presented using 470 mu b(-1) of Pb+Pb collisions at root s(NN) = 5.02 TeV with the ATLAS detector at the LHC. These cumulants provide information on the event-by-event fluctuations of single harmonics p(v(n)). For the first time, a negative c(1){4} is observed. The c(4){4} is found to be negative in central collisions but changes sign around 20-25% centrality. This behavior is consistent with a nonlinear contribution to v(4) that is proportional to v(2)(2). c(2){4} and c(3){4} are calculated using two reference event classes in order to investigate the influence of volume fluctuations. Over most of the centrality range, c(2){4} and c(3){4} are found to be negative, while in the ultra-central collisions, c(2){4} changes sign and becomes positive, suggesting a deviation from Gaussian behavior in the event-by-event fluctuation of v(2). The magnitudes of the sign change are also found to be dependent of the event class definition .

Measurements of four-particle cumulants c(n){4} for n = 1, 2, 3, 4 are presented using 470 mu b(-1) of Pb+Pb collisions at root s(NN) = 5.02 TeV with the ATLAS detector at the LHC. These cumulants provide information on the event-by-event fluctuations of single harmonics p(v(n)). For the first time, a negative c(1){4} is observed. The c(4){4} is found to be negative in central collisions but changes sign around 20-25% centrality. This behavior is consistent with a nonlinear contribution to v(4) that is proportional to v(2)(2). c(2){4} and c(3){4} are calculated using two reference event classes in order to investigate the influence of volume fluctuations. Over most of the centrality range, c(2){4} and c(3){4} are found to be negative, while in the ultra-central collisions, c(2){4} changes sign and becomes positive, suggesting a deviation from Gaussian behavior in the event-by-event fluctuation of v(2). The magnitudes of the sign change are also found to be dependent of the event class definition .

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