Abstract
In the hydrodynamic model description of heavy-ion collisions, the elliptic flow and triangular flow are sensitive to the quadrupole deformation and octupole deformation of the colliding nuclei. The relations between and have recently been clarified and were found to follow a simple parametric form. The STAR Collaboration has just published precision data from isobaric and collisions, where they observe large differences in central collisions and . Using a transport model simulation, we show that these orderings are a natural consequence of and . We reproduce the centrality dependence of the ratio qualitatively and ratio quantitatively and extract values of and that are consistent with those measured at low-energy nuclear structure experiments. STAR data provide the first direct evidence of strong octupole correlations in the ground state of in heavy-ion collisions. Our analysis demonstrates that flow measurements in high-energy, heavy-ion collisions, especially using isobaric systems, are a new precision tool to study nuclear structure physics.
- Received 30 September 2021
- Accepted 9 December 2021
DOI:https://doi.org/10.1103/PhysRevLett.128.022301
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