Evidence for Similar Collectivity of High Transverse-Momentum Particles in 𝑝-Pb and Pb-Pb Collisions

Abstract

Charged hadron elliptic anisotropies (𝑣2) are presented over a wide transverse momentum (𝑝T) range for proton-lead (𝑝⁢Pb) and lead-lead (PbPb) collisions at nucleon-nucleon center-of-mass energies of 8.16 and 5.02 TeV, respectively. The data were recorded by the CMS experiment and correspond to integrated luminosities of 186 and 0.607 nb−1 for the 𝑝⁢Pb and PbPb systems, respectively. A four-particle cumulant analysis is performed using subevents separated in pseudorapidity to effectively suppress noncollective effects. At high 𝑝T (𝑝T>8 GeV), significant positive 𝑣2 values that are similar between 𝑝⁢Pb and PbPb collisions at comparable charged particle multiplicities are observed. This observation suggests a common origin for the multiparticle collectivity for high-𝑝T particles in the two systems.