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 R u + R u and Z r + Z r at s N N = 200 GeV, we show that any deviation of the midrapidity ratio N B / N Q from the valence-correlated charge-to-baryon ratio baseline, A / Z —often referred to as excess baryon stopping—can be quantitatively extracted from 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 OY , whose central-to-peripheral ratio, R O Y , exhibits strong and systematic sensitivity to the neutron-skin thickness of the target nucleus Y .