Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of $\mathrm{U}+\mathrm{U}$ at $\sqrt{s_{\mathrm{NN}}}=193\mathrm{GeV}$, $\mathrm{Cu}+\mathrm{Au}$ at $\sqrt{s_{\mathrm{NN}}}=200\mathrm{GeV}$ and $\mathrm{Au}+\mathrm{Au}$ spanning the range $\sqrt{s_{\mathrm{NN}}}=11.5–200\mathrm{GeV}$. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and trento model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.

• Received 25 January 2022
• Revised 17 August 2022
• Accepted 16 November 2022

DOI:https://doi.org/10.1103/PhysRevLett.129.252301