Global polarization of Λ Λ hyperons in Pb-Pb collisions at sNN = 2.76 and 5.02 TeV

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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<pT<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%.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • Homi Bhabha National Institute
  • Niels Bohr Institute
  • University of Copenhagen
  • Variable Energy Cyclotron Centre
  • University of Brescia
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Subatomär fysik
Originalspråkengelska
Artikelnummer044611
TidskriftPhysical Review C
Volym101
Utgåva nummer4
StatusPublished - 2020 apr 20
PublikationskategoriForskning
Peer review utfördJa