Left-right splitting of elliptic flow in heavy ion collisions: TRENTo-3D initialization and CLVisc hydrodynamic simulations

TL;DR

This study uses advanced initial condition modeling and hydrodynamic simulations to analyze the left-right splitting of elliptic flow in heavy-ion collisions, revealing dependencies on flow harmonics, transverse momentum scale, and initial state features.

Contribution

It introduces a comprehensive analysis of $ ext{Δ}v_{2}$ splitting using TRENTo-3D and CLVisc, highlighting the roles of odd flow harmonics and sub-nucleonic structures.

Findings

$ ext{Δ}v_{2}$ depends on odd flow harmonics and $v_{2}$.

Transverse momentum scale $k_ ext{T}$ influences fireball tilt and rapidity dependence.

$ ext{Δ}v_{2}$ is sensitive to sub-nucleonic degrees of freedom and initial state uncertainties.

Abstract

Using the TRENTo-3D initial condition model coupled with (3+1)-dimensional CLVisc hydrodynamic simulations, we systematically investigate the left-right splitting of elliptic flow ($\Delta v_{2}$) for soft particles in relativistic heavy-ion collisions. Our study reveals that the final distribution characteristics of $\Delta v_{2}$ are primarily depend on the odd flow harmonics and $v_{2}$ itself. We find that the parton transverse momentum scale $k_\mathrm{T}$ not only determines the geometric tilt of the QGP fireball but also significantly affects the rapidity dependence of both $v_1$ and $\Delta v_{2}$, providing new insights into the splitting mechanism of $\Delta v_{2}$. Furthermore, our results demonstrate that $\Delta v_{2} (p_\mathrm{T})$ exhibits significant sensitivity to influences such as the sub-nucleonic degrees of freedom (or `hotspots'), transverse momentum scale, and fragmentation region profile. By analyzing the $\Delta v_{2}$ and $\Delta v_{2}/v_{2}$ ratio, our findings provide new constraints on the uncertainties of the QGP initial state and provide additional constraints for refining model parameters.