Measurement of multi-particle azimuthal correlations in pp, p + Pb and low-multiplicity Pb + Pb collisions with the ATLAS detector
Date
2017
Authors
Aaboud, M.
Albert, Justin
Chiu, Y. H.
Elliot, Alison A.
Fincke-Keeler, J.
Hamano, Kenji
Hill, Ewan Chin
Keeler, Richard
Kowalewski, Robert
Kuwertz, E. S.
Journal Title
Journal ISSN
Volume Title
Publisher
The European Physical Journal C
Abstract
Multi-particle cumulants and corresponding Fourier harmonics are measured for azimuthal angle distributions of charged particles in pp collisions at s√ = 5.02 and 13 TeV and in p + Pb collisions at sNN−−−√ = 5.02 TeV, and compared to the results obtained for low-multiplicity Pb + Pb collisions at sNN−−−√ = 2.76 TeV. These measurements aim to assess the collective nature of particle production. The measurements of multi-particle cumulants confirm the evidence for collective phenomena in p + Pb and low-multiplicity Pb + Pb collisions. On the other hand, the pp results for four-particle cumulants do not demonstrate collective behaviour, indicating that they may be biased by contributions from non-flow correlations. A comparison of multi-particle cumulants and derived Fourier harmonics across different collision systems is presented as a function of the charged-particle multiplicity. For a given multiplicity, the measured Fourier harmonics are largest in Pb + Pb, smaller in p + Pb and smallest in pp collisions. The pp results show no dependence on the collision energy, nor on the multiplicity.
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Citation
Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; … & Zwalinski, L. (2017). Measurement of multi-particle azimuthal correlations in pp, p + Pb and low-multiplicity Pb + Pb collisions with the ATLAS detector. The European Physical Journal C, 77(6), article 428. DOI: 10.1140/epjc/s10052-017-4988-1