Determine the neutron skin type by relativistic isobaric collisions

TL;DR

This paper investigates how neutron skin types influence collision observables in relativistic isobaric collisions, proposing a method to determine neutron skin characteristics and nuclear deformities using elliptic flow data.

Contribution

It introduces a novel approach to identify neutron skin types through collision data analysis and demonstrates the effectiveness of halo-type density models as surrogates for DFT densities.

Findings

Ru+Ru/Zr+Zr ratios are sensitive to neutron skin type

DFT calculations favor halo-type neutron skin

Halo density can effectively probe nuclear deformities

Abstract

The effects of neutron skin on the multiplicity ($N_{\rm ch}$) and eccentricity($\epsilon_2$) in relativistic $^{96}_{44}$Ru+$^{96}_{44}$Ru and $^{96}_{40}$Zr+$^{96}_{40}$Zr collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV are investigated with the Trento model. It is found that the Ru+Ru/Zr+Zr ratios of the $N_{\rm ch}$ distributions and $\epsilon_{2}$ in mid-central collisions are exquisitely sensitive to the neutron skin type (skin vs.~halo). The state-of-the-art calculations by energy density functional theory (DFT) favor the halo-type neutron skin and can soon be confronted by experimental data. It is demonstrated that the halo-type density can serve as a good surrogate for the DFT density, and thus can be efficiently employed to probe nuclear deformities by using elliptic flow data in central collisions. We provide hereby a proof-of-principle venue to simultaneously determine the neutron skin type, thickness, and nuclear deformity.