Energy dependence of heavy-ion initial condition in isobar collisions

Understand

Collisions of isobar nuclei, those with the same mass number but different structure parameters, provide a new way to probe the initial condition of the heavy ion collisions.

• Using transport model simulation of $^{96}$Ru+$^{96}$Ru and $^{96}$Zr+$^{96}$Zr collisions at two energies $\sqrt{s_{\mathrm{NN}}}=0.2$ TeV and 5.02 TeV, where $^{96}$Ru and $^{96}$Zr nuclei have significantly different deformations and radial profiles, we identify sources of eccentricities contributing independently to the final state harmonic flow $v_n$.
• The efficacy for flow generation differs among these sources, and explains the modest energy dependence of the isobar ratios of $v_n$.
• Additionally, a significant component of $v_n$ is found to be uncorrelated with the eccentricity but is instead generated dynamically during system evolution.