Speaker
Description
Ultra-relativistic heavy-ion collisions create a unique environment for studying the quark–gluon plasma (QGP). In non-central collisions, the large initial orbital angular momentum can be transferred to the medium as vorticity, inducing a global polarization of produced particles. Furthermore, the strong initial magnetic field generated in heavy-ion collisions can contribute to the global polarization, leading to competing effects to particle and anti-particle based on their electric charge.
This talk presents new results from the ALICE experiment using high-
statistics data from LHC Run 3. We report the first observation of global $\Lambda$ hyperon polarization in Pb–Pb collisions at $\sqrt{s_{NN}}$ = 5.36 TeV. These measurements offer a direct probe into the vortical dynamics of the medium and into the interplay between spin and orbital angular momentum in strongly interacting matter.
Complementing the hyperon studies, we investigate the production and polarization of vector mesons, which are essential for understanding particle production mechanisms and hadronization from polarized quarks. We present preliminary $\phi$ meson $p_T$ spectra across various centrality classes in Pb–Pb collisions at $\sqrt{s_{NN}}$ = 5.36 TeV, alongside results from pp collisions at $\sqrt{s_{NN}}$ = 13.6 TeV. The $\phi$ meson is reconstructed via the dimuon channel at forward rapidity, with the pp data providing a vital reference for interpreting polarization effects. Finally, these results are compared with previous measurements and theoretical predictions from various Monte Carlo models to further constrain our understanding of strongly interacting matter.