Quark Matter 2025

Spin Polarization in Heavy-Ion Collisions: Effects of Late-Stage Spin Dynamics

Not scheduled

20m

Goethe University Frankfurt, Campus Westend, Theodor-W.-Adorno-Platz 1, 60629 Frankfurt am Main, Germany

Poster Chirality Poster session 2

Speaker

Nils Sass

Description

In 2017, the STAR collaboration at RHIC unveiled the global polarization of $\mathrm{\Lambda }$ hyperons, establishing a connection between angular momentum in heavy-ion collisions and the vorticity of the quark-gluon plasma (QGP). However, a comprehensive understanding of how spin-states - and thus polarization - evolve throughout the hadronic phase presents a significant challenge. This study investigates the impact of spin-flip processes during (in)elastic scatterings on $\mathrm{\Lambda }$ polarization in the hadronic rescattering phase.
We incorporate spin-flip cross sections, derived from both s- and t-channel processes as calculated by Sung, Ko, and Lee [arXiv:2404.15890v1], into the SMASH-vHLLE hybrid approach. This integration enables a dynamic representation of spin states within the hadronic transport regime. Our research systematically implements spin-flip effects in hadronic transport simulations, yielding critical insights into the late-stage evolution of polarization in heavy-ion collisions. The findings hold direct relevance for interpreting experimental results from RHIC and the LHC, advancing our understanding of spin dynamics in the context of QCD.

Presentation materials

Poster_SpinPolarization.pdf