A "breathing'' octupole $^{208}$Pb nucleus: resolving the elliptical-to-triangular azimuthal anisotropy puzzle in ultracentral relativistic heavy ion collisions

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Xu, Hao-jie, Xu, Duoduo, Zhao, Shujun, Zhao, Wenbin, Song, Huichao, Wang, Fuqiang
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915291314782208
author Xu, Hao-jie
Xu, Duoduo
Zhao, Shujun
Zhao, Wenbin
Song, Huichao
Wang, Fuqiang
author_facet Xu, Hao-jie
Xu, Duoduo
Zhao, Shujun
Zhao, Wenbin
Song, Huichao
Wang, Fuqiang
contents Relativistic heavy ion collisions provide a unique opportunity to probe the nuclear structure by taking an instantaneous snapshot of the colliding nuclei and converting it into momentum anisotropies of final emitted hadrons. A long-standing puzzle of too large a ratio of the elliptical-to-triangular ($v_{2}$-to-$v_{3}$) anisotropies in ultracentral $^{208}$Pb+$^{208}$Pb collisions at the Large Hadron Collider(LHC) cannot be solved simply by hydrodynamic simulations with initial conditions containing the spherical or certain deformed shape of $^{208}$Pb. In this Letter, using the iEBE-VISHNU relativistic viscous hydrodynamic hybrid model simulations with the Trento initial condition, we show that a dynamic octupole deformation--a shape-breathing of $^{208}$Pb --could potentially solve the $v_{2}$-to-$v_{3}$ puzzle and simultaneously describe the $v_3\{4\}$ data measured in experiment. Our results highlight the unique capability of capturing transient collective properties of nuclei on yoctosecond ($10^{-24}$~s) timescales, unfeasible with low-energy nuclear reactions.
format Preprint
id arxiv_https___arxiv_org_abs_2504_19644
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A "breathing'' octupole $^{208}$Pb nucleus: resolving the elliptical-to-triangular azimuthal anisotropy puzzle in ultracentral relativistic heavy ion collisions
Xu, Hao-jie
Xu, Duoduo
Zhao, Shujun
Zhao, Wenbin
Song, Huichao
Wang, Fuqiang
Nuclear Theory
Nuclear Experiment
Relativistic heavy ion collisions provide a unique opportunity to probe the nuclear structure by taking an instantaneous snapshot of the colliding nuclei and converting it into momentum anisotropies of final emitted hadrons. A long-standing puzzle of too large a ratio of the elliptical-to-triangular ($v_{2}$-to-$v_{3}$) anisotropies in ultracentral $^{208}$Pb+$^{208}$Pb collisions at the Large Hadron Collider(LHC) cannot be solved simply by hydrodynamic simulations with initial conditions containing the spherical or certain deformed shape of $^{208}$Pb. In this Letter, using the iEBE-VISHNU relativistic viscous hydrodynamic hybrid model simulations with the Trento initial condition, we show that a dynamic octupole deformation--a shape-breathing of $^{208}$Pb --could potentially solve the $v_{2}$-to-$v_{3}$ puzzle and simultaneously describe the $v_3\{4\}$ data measured in experiment. Our results highlight the unique capability of capturing transient collective properties of nuclei on yoctosecond ($10^{-24}$~s) timescales, unfeasible with low-energy nuclear reactions.
title A "breathing'' octupole $^{208}$Pb nucleus: resolving the elliptical-to-triangular azimuthal anisotropy puzzle in ultracentral relativistic heavy ion collisions
topic Nuclear Theory
Nuclear Experiment
url https://arxiv.org/abs/2504.19644