Measurement of multi-particle azimuthal correlations in pp, p + Pb and low-multiplicity Pb + Pb collisions with the ATLAS detector
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 √{s_{_ {NN}}} = 5.02 TeV, and compared to the results obtained for low-multiplicity Pb + Pb collisions at √{s_{_ {NN}}} = 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.
- Publication:
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European Physical Journal C
- Pub Date:
- June 2017
- DOI:
- 10.1140/epjc/s10052-017-4988-1
- arXiv:
- arXiv:1705.04176
- Bibcode:
- 2017EPJC...77..428A
- Keywords:
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- High Energy Physics - Experiment;
- Nuclear Experiment
- E-Print:
- 54 pages in total, author list starting page 38, 17 figures, 10 tables, final version published in EPJC, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2015-14/