Nucleon Size Independence of Hadronic Nucleus-Nucleus Cross Sections

Recent proposals to constrain the nucleon size using hadronic cross sections (${\sigma }_{\mathrm{A}\mathrm{A}}$) conflict with collective flow data. I demonstrate this dependence is an artifact of ``geometric inflation,‘’ where smearing point-like nucleons unintentionally dilutes the nuclear surface. By implementing a self-consistent framework that preserves the global nuclear density, I show that ${\sigma }_{\mathrm{A}\mathrm{A}}$ is essentially insensitive to the nucleon width. This establishes ${\sigma }_{\mathrm{A}\mathrm{A}}$ as a robust probe of the nuclear surface rather than the sub-nucleon scale. Utilizing this property, I extract a neutron skin thickness for ${}^{208}$Pb of $\mathrm{\Delta }{r}_{\mathrm{n}\mathrm{p}}\in [0,0.24]$~fm, providing an unconventional way to constrain the nuclear symmetry energy using high-energy hadronic observables.