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

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 ($\hat{I}”v_2$) for soft particles in relativistic heavy-ion collisions. Our study reveals that the final distribution characteristics of $\hat{I}”v_2$ 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 $\hat{I}”v_2$, providing new insights into the splitting mechanism of $\hat{I}”v_2$. Furthermore, our results demonstrate that $\hat{I}”v_2(p_{\mathrm{T}})$ 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 $\hat{I}”v_2$ and $\hat{I}”v_2/v_2$ ratio, our findings provide new constraints on the uncertainties of the QGP initial state and provide additional constraints for refining model parameters.

9 pages, 8 figures, comments are welcome