Orateur
Chenyan Li
Description
The observation of hyperon polarization along beam direction ($P_z$) in nucleus-nucleus collisions has revealed the relationship between collective flow and the complex vortical structures of the quark-gluon plasma (QGP). With the high-statistics data collected by the CMS experiment, we present the first $P_z$ results in proton-lead collisions at $\sqrt{s_{NN}}= 8.16$ TeV over a wide transverse momentum range for $\Lambda$ and $\bar{\Lambda}$ particles at low- and high-multiplicity events. The measured $P_z$ signal can shed light on the mechanism of spin polarization in QGP as well as the origin of collectivity in small collision systems.
