A1 Journal article (refereed)
Global polarization of ΛΛ¯ hyperons in Pb-Pb collisions at √sNN = 2.76 and 5.02 TeV (2020)

ALICE Collaboration. (2020). Global polarization of ΛΛ¯ hyperons in Pb-Pb collisions at √sNN = 2.76 and 5.02 TeV. Physical Review C, 101(4), Article 044611. https://doi.org/10.1103/PhysRevC.101.044611

JYU authors or editors

Publication details

All authors or editors: ALICE Collaboration

Journal or series: Physical Review C

ISSN: 2469-9985

eISSN: 2469-9993

Publication year: 2020

Volume: 101

Issue number: 4

Article number: 044611

Publisher: American Physical Society

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1103/PhysRevC.101.044611

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/69056

Web address of parallel published publication (pre-print): https://arxiv.org/abs/1909.01281

Abstract

The global polarization of the Λ and Λ¯ hyperons is measured for Pb-Pb collisions at √sNN=2.76 and 5.02 TeV recorded with the ALICE at the Large Hadron Collider (LHC). The results are reported differentially as a function of collision centrality and hyperon's transverse momentum (pT) for the range of centrality 5–50%, 0.5<5 GeV/c, and rapidity |y|<0.5. The hyperon global polarization averaged for Pb-Pb collisions at √sNN=2.76 and 5.02 TeV is found to be consistent with zero, ⟨PH⟩(%)≈0.01±0.06(stat.)±0.03(syst.) in the collision centrality range 15–50%, where the largest signal is expected. The results are compatible with expectations based on an extrapolation from measurements at lower collision energies at the Relativistic Heavy Ion Collider, hydrodynamical model calculations, and empirical estimates based on collision energy dependence of directed flow, all of which predict the global polarization values at LHC energies of the order of 0.01%.

Keywords: particle physics

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2020

JUFO rating: 2