Disentangling baryon stopping and neutron skin effects in heavy-ion collisions

TL;DR

This paper uses a statistical model to analyze baryon and charge stopping in heavy-ion collisions, proposing new observables to extract nuclear structure information like neutron-skin thickness from experimental data.

Contribution

It introduces a method to extract baryon-stopping parameters and a new observable sensitive to neutron-skin thickness in heavy-ion collisions.

Findings

Baryon-stopping parameter $oldsymbol{}$ can be extracted from RHIC data.

The $r^{OX}$ observable is sensitive to neutron-skin thickness.

The approach generalizes to various collision systems at RHIC and LHC.

Abstract

We analyse the net baryon (B) and net electric charge (Q) stopping in heavy-ion collisions using the statistical model. Focusing first on isobar collisions $\rm{Ru}+\rm{Ru}$ and $\rm{Zr}+\rm{Zr}$ at $\sqrt{s_{\rm NN}}=200$~GeV, we show that the excess baryon-stopping parameter $\gamma_B \equiv (N_B/N_Q)\,(Z/A)$ can be quantitatively extracted from forthcoming RHIC measurements of charge- and baryon-stopping ratios. We then generalize the approach to other collision systems at RHIC and LHC energies and introduce an oxygen-baseline observable, $r^{OX}$, whose central-to-peripheral ratio exhibits strong and systematic sensitivity to the neutron-skin thickness of the target nucleus $X$.