Precision tests of the nonlinear mode coupling of anisotropic flow via high-energy collisions of isobars

Abstract

Valuable information on the dynamics of expanding fluids can be inferred from the response of such systems to perturbations in their initial geometry. We apply this technique in high-energy ${}^{96}$Ru+${}^{96}$Ru and ${}^{96}$Zr+${}^{96}$Zr collisions to scrutinize the expansion dynamics of the quark-gluon plasma, where the initial geometry perturbations are sourced by the differences in deformations and radial profiles between ${}^{96}$Ru and ${}^{96}$Zr, and the collective response is captured by the change in anisotropic flow $V_n$ between the two collision systems. Using a transport model, we analyze how the nonlinear coupling between lower-order flow harmonics $V_2$ and $V_3$ to the higher-order flow harmonics $V_4$ and $V_5$, expected to scale as $V_{4\mathrm{NL}}={\chi }_4{V}_2^2$ and $V_{5\mathrm{NL}}={\chi }_5{V}_2{V}_3$, gets modified as one moves from ${}^{96}$Ru+${}^{96}$Ru to ${}^{96}$Zr+${}^{96}$Zr systems. We find that these scaling relations are valid to high precision: variations of order 20\% in $V_{4\mathrm{NL}}$ and $V_{5\mathrm{NL}}$ due to differences in quadrupole deformation, octupole deformation, and nuclear skin modify ${\chi }_4$ and ${\chi }_5$ by about 1--2\%. Percent-level deviations are however larger than the expected experimental uncertainties and could be measured. Therefore, collisions of isobars with different nuclear structures are a unique tool to isolate subtle nonlinear effects in the expansion of the quark-gluon plasma that would be otherwise impossible to access in a single collision system.

6 pages, 3 figures

References in corpus (9)

• Glauber Modeling in High Energy Nuclear Collisions
• Triangularity and Dipole Asymmetry in Heavy Ion Collisions
• $v_4$, $v_5$, $v_6$, $v_7$: nonlinear hydrodynamic response versus LHC data
• Evidence of quadrupole and octupole deformations in ${}^{96}$Zr+${}^{96}$Zr and ${}^{96}$Ru+${}^{96}$Ru collisions at ultra-relativistic energies
• Viscous Effects on the Mapping of the Initial to Final State in Heavy Ion Collisions
• Scaling approach to nuclear structure in high-energy heavy-ion collisions
• Hydrodynamic flow amplitude correlations in event-by-event fluctuating heavy-ion collisions
• Ratios of collective flow observables in high-energy isobar collisions are insensitive to final state interactions
• The fluctuations of quadrangular flow

Cited by in corpus (8)

• Separating the impact of nuclear skin and nuclear deformation in high-energy isobar collisions
• Probe nuclear structure using the anisotropic flow at the Large Hadron Collider
• Signature of the $\alpha$-clustering structure of Light Nuclei in Relativistic Nuclear Collisions
• Momentum dependent flow correlations in deformed nuclei at collision energies available at the BNL Relativistic Heavy Ion Collider
• The elliptic flow difference between baryons and anti-baryons in heavy collision with SMASH Model
• Exploring Rapidity-Even Dipolar Flow in Isobaric Collisions at RHIC
• Influence of Cluster Configurations and Nucleon--Nucleon Scattering Cross-Section on Stopping Power in Heavy-Ion Collisions
• A Method to Constrain Preferential Emission and Spectator Dynamics in Heavy-Ion Collisions