Exploring electromagnetic field effects and constraining transport parameters of QGP using STAR BES-II data

Abstract

Heavy-ion collisions undergo various stages in their evolution and it is crucial to disentangle the initial- and final-stage effects. In this work, we report measurements of two types of observables: (i) charge-dependent directed flow (Δv1), which is sensitive to the initial ultra-strong electromagnetic fields, and (ii) flow correlations, such as rn(η) which is sensitive to the initial longitudinal de-correlation, and correlations among flow harmonics. These measurements contribute to constraining the initial state of the collisions, and through a comprehensive beam energy scan, we gain significant insights into the system evolution in the presence of initial spatial asymmetry and electromagnetic fields.