Speaker
Description
Nuclear structure theory provides point-nucleon densities, whereas high-energy nuclear collisions probe nuclei through finite-resolution hadronic interactions. When point densities are used as nucleon-center distributions in Monte Carlo initial-state models, varying the nucleon width changes both the interaction range and the folded nuclear surface. This resolution mismatch obscures the separation between nuclear structure and collision dynamics.
In this talk, I show that geometric surface inflation accounts for most of the strong nucleon-width dependence of the hadronic cross section, $\sigma_{\rm AA}$, used in recent Bayesian analyses. Holding fixed the folded density entering the Glauber phase shift removes this ambiguity, making $\sigma_{\rm AA}$ nearly insensitive to a Gaussian nucleon width and primarily sensitive to the nuclear surface. Within a two-component model, the measured cross section corresponds to a neutron-skin interval $\Delta r_{\rm np}\in[0,0.21]$ fm for $^{208}$Pb. These results establish resolution matching as a consistency requirement for connecting point-nucleon nuclear structure with finite-resolution heavy-ion collision models.
