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

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 $\mathrm{R}\mathrm{u}+\mathrm{R}\mathrm{u}$ and $\mathrm{Z}\mathrm{r}+\mathrm{Z}\mathrm{r}$ at $\sqrt{s_{\mathrm{N}\mathrm{N}}}=200$~GeV, we show that the excess baryon-stopping parameter ${\gamma }_B\equiv (N_B\mathrm{/}{N}_Q)(Z\mathrm{/}A)$ 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 $X$.