Strange hadron collectivity in pPb and PbPb collisions

ARXIV EPRINT: 2205.00080 (https://arxiv.org/abs/2205.00080).Copyright © 2023 CERN, for the benefit of the CMS Collaboration. The collective behavior of $${\textrm{K}}_{\textrm{S}}^0$$ K S 0 and $$\Lambda /\overline{\Lambda}$$ Λ / Λ ¯ strange hadrons is studied by measuring the elliptic azimuthal anisotropy (v2) using the scalar-product and multiparticle correlation methods. Proton-lead (pPb) collisions at a nucleon-nucleon center-of-mass energy $$\sqrt{s_{\textrm{NN}}}$$ s NN = 8.16 TeV and lead-lead (PbPb) collisions at $$\sqrt{s_{\textrm{NN}}}$$ s NN = 5.02 TeV collected by the CMS experiment at the LHC are investigated. Nonflow effects in the pPb collisions are studied by using a subevent cumulant analysis and by excluding events where a jet with transverse momentum greater than 20 GeV is present. The strange hadron v2 values extracted in pPb collisions via the four- and six-particle correlation method are found to be nearly identical, suggesting the collective behavior. Comparisons of the pPb and PbPb results for both strange hadrons and charged particles illustrate how event-by-event flow fluctuations depend on the system size.SCOAP