Measurement of longitudinal flow decorrelations in Pb+Pb collisions at √sNN = 2.76 and 5.02 TeV with the ATLAS detector

Rimoldi, Marco; Mullier, Geoffrey; Miucci, Antonio; Merlassino, Claudia; Haug, Sigve; Weber, Michael; Meloni, Federico; Beck, Hans Peter; Ereditato, Antonio (2018). Measurement of longitudinal flow decorrelations in Pb+Pb collisions at √sNN = 2.76 and 5.02 TeV with the ATLAS detector. European physical journal. C - particles and fields, 78(2) EDP Sciences 10.1140/epjc/s10052-018-5605-7

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Measurements of longitudinal flow correlations are presented for charged particles in the pseudorapidity range |η| < 2.4 using 7 μb⁻¹ and 470 μb⁻¹ of Pb+Pb collisions at √sNN = 2.76 and 5.02 TeV, respectively, recorded by the ATLAS detector at the LHC. It is found that the correlation between the harmonic flow coefficients vn measured in two separated η intervals does not factorise into the product of single-particle coefficients, and this breaking of factorisation, or flow decorrelation, increases linearly with the η separation between the intervals. The flow decorrelation is stronger at 2.76 TeV than at 5.02 TeV. Higher-order moments of the correlations are also measured, and the corresponding
linear coefficients for the kth-moment of the vn are found to be proportional to k for v₃, but not for v₂. The decorrelation effect is separated into contributions from the magnitude of
vn and the event-plane orientation, each as a function of η. These two contributions are found to be comparable. The longitudinal flow correlations are also measured between vn
of different order in n. The decorrelations of v₂ and v₃ are found to be independent of each other, while the decorrelations of v₄ and v₅ are found to be driven by the nonlinear
contribution from v₂² and v₂v₃, respectively.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP)

UniBE Contributor:

Haug, Sigve; Weber, Michael and Beck, Hans Peter


500 Science > 530 Physics




EDP Sciences





Date Deposited:

20 Jun 2019 10:18

Last Modified:

13 Mar 2021 17:16

Publisher DOI:


Additional Information:

Kollaboration - Es sind nur die Berner Autoren namentlich erwaehnt




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