The influence of electromagnetic fields on the generation of the directed and elliptic flows of heavy quark in relativistic heavy-ion collisions

TL;DR

This study investigates how electromagnetic fields generated during heavy-ion collisions influence the directed and elliptic flows of heavy quarks, revealing electromagnetic effects on $v_1$ but minimal impact on $v_2$.

Contribution

It provides a dynamic calculation of electromagnetic fields and their effect on heavy quark flow, aligning with experimental data and highlighting the role of electromagnetic splitting in $v_1$.

Findings

Electromagnetic fields cause a splitting in $v_1$ between $D^0$ and $ar{D}^0$ mesons.

The electromagnetic effects are more prominent in $v_1$ than in $v_2$.

The model reproduces experimental $v_1$ splitting data.

Abstract

We study the impact of self-generated electromagnetic fields (EMF) on the charm quarks momentum evolution in the partonic and hadronic medium created in heavy-ion collisions at RHIC energy within the Parton-Hadron-String Dynamics (PHSD) off-shell transport approach. In the quark-gluon plasma (QGP) phase, the charm quark interacts with the off-shell partons whose mass and widths are given by the Dynamical Quasi-Particle Model (DQPM), which can reproduce the lattice QCD thermodynamics. The background electromagnetic fields are computed dynamically within the PHSD considering both the spectators and participants protons as well as newly produced charged hadrons, quarks, and antiquarks, which reflects naturally the electric conductivity $\sigma_{el}$ of the medium. We study the directed and elliptic flow of the $D$ mesons in the presence of the electromagnetic fields. We find that electromagnetically induced splitting in the $D$ meson $v_1$ through $D^0$ and $\overline{D}^0$ mesons is consistent with the experimental data. Furthermore, we notice that the splitting in the heavy quark $v_1$ as a function of $p_T$ is more prominent as a probe of the produced electromagnetic fields. However, we find only a small impact of electromagnetic fields on the heavy quark elliptic flow $v_2$.