Transverse momentum and process dependent azimuthal anisotropies in root S-NN=8.16 TeV p plus Pb collisions with the ATLAS detector

Journal article

The azimuthal anisotropy of charged particles produced in sNN=8.16 TeV p+Pb collisions is measured with the ATLAS detector at the LHC. The data correspond to an integrated luminosity of 165 nb - 1 that was collected in 2016. Azimuthal anisotropy coefficients, elliptic v2 and triangular v3, extracted using two-particle correlations with a non-flow template fit procedure, are presented as a function of particle transverse momentum (pT) between 0.5 and 50 GeV. The v2 results are also reported as a function of centrality in three different particle pT intervals. The results are reported from minimum-bias events and jet-triggered events, where two jet pT thresholds are used. The anisotropies for particles with pT less than about 2 GeV are consistent with hydrodynamic flow expectations, while the significant non-zero anisotropies for pT in the range 9–50 GeV are not explained within current theoretical frameworks. In the pT range 2–9 GeV, the anisotropies are larger in minimum-bias than in jet-triggered events. Possible origins of these effects, such as the changing admixture of particles from hard scattering and the underlying event, are discussed.

Authors: Aaboud, M; Aad, G; Abbott, B; Abbott, DC; Abdinov, O

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Nature
• Journal: European Physical Journal C
• Volume: 80
• Issue: 1
• Article number: 73
• Publication date: 2020-01-30
• Acceptance date: 2020-01-07
• DOI: 10.1140/epjc/s10052-020-7624-4
• EISSN: 1434-6052
• ISSN: 1434-6044
• Language: English
• Keywords: FFR