Impact of nuclear structure on the CME background in $^{96}_{44}$Ru + $^{96}_{44}$Ru and $^{96}_{40}$Zr + $^{96}_{40}$Zr collisions at $\sqrt{s_{NN}}$ = 7.7 $\sim$ 200 GeV from a multiphase transport model

TL;DR

This study uses a multiphase transport model to explore how nuclear structure influences multiplicity and flow differences in isobaric collisions, revealing deformation effects are most prominent in central collisions and vary with energy.

Contribution

It provides a detailed analysis of nuclear deformation effects on collision observables across different energies using the AMPT model, highlighting the role of nuclear structure in CME background.

Findings

Quadrupole deformation affects $v_2$ mainly in central collisions.

Octupole deformation influences $v_2$ in near-central collisions.

Neutron skin effect dominates in mid-central collisions.

Abstract

Impacts of nuclear structure on multiplicity ($N_{ch}$) and anisotropic flows ($v_{2}$ and $v_{3}$) in the isobaric collisions of $^{96}_{44}$Ru + $^{96}_{44}$Ru and $^{96}_{40}$Zr + $^{96}_{40}$Zr at $\sqrt{s_{NN}}$ = 7.7, 27, 62.4 and 200 GeV are investigated by using the string melting version of A MultiPhase Transport (AMPT) model. In comparison with the experimental data released recently by the STAR collaboration, it is found that the impact of quadrupole deformation $\beta_{2}$ on the $v_{2}$ difference is mainly manifested in the most central collisions, while the octupole deformation $\beta_{3}$ is in the near-central collisions, and the neutron skin effect dominates in the mid-central collisions. Viewing from the energy dependence, these effects are magnified at lower energies.