Conveners
Parallel session 1: Chirality I
- Qun Wang (University of Science and Technology of China)
In non-central heavy ion collisions, substantial angular momentum is generated, resulting in significant vorticity and the spin polarization of particles with finite spin along the global angular momentum. Additionally, anisotropic flow can produce local vorticities in both in-plane (z) and out-of-plane (y) directions, leading to local polarization. The RHIC Beam Energy Scan II (BES-II)...
Approximately fifty years ago, the polarization of $\Lambda$ hyperons produced in unpolarized proton-beryllium collisions was discovered, though the origin of this phenomenon remains elusive. Many studies indicate that final-state effects, particularly from hadronization, play a significant role. Recently, it has been proposed that spin correlations of $\Lambda$ hyperons could provide insight...
Chiral Magnetic Effect (CME) is a phenomenon in which electric charge is separated by a strong magnetic field from local domains of chirality imbalance and parity violation in quantum chromodynamics. The CME-sensitive observable, charge-dependent azimuthal correlator $\Delta\gamma$, is contaminated by a major physics background proportional to the elliptic flow ($v_{2}$) of particles of...
The interplay between the chiral anomaly and strong magnetic or vortical fields generated in off-central heavy-ion collisions is theorized to produce anomalous chiral effects in the quark–gluon plasma, such as the Chiral Magnetic Effect (CME) and the Chiral Vortical Effect (CVE). These effects have been actively studied by several experiments for over a decade as they could shed light on the...
In recent years, there has been a growing interest in the study of spin-polarization effects in heavy-ion collisions. Most approaches assume that final-state particles become polarized only if the thermal vorticity and shear are non-zero at freeze-out. In this sense, polarization is a final-state effect. Here, we propose a different polarization mechanism. For the first time, spin density is...
The $\Lambda$ polarization is a crucial probe of the gradients of velocity and temperature in the quark-gluon plasma generated in heavy-ion collisions. However, it is still not systematically used to tune hydrodynamic models. In this talk, we investigate the influence of different initial conditions and parametrization of the bulk viscosity on $\Lambda$ polarization, showing that they affect...
