Effect of Fine Radial Structure in Nuclear Density Distributions on Heavy-Ion Collison Observables

The final state observables in heavy-ion collisions depend critically on the states of initial ions, which are governed by the nuclear density distributions. A common approach for modeling a density distribution is to estimate it with a 2-parameter Fermi function (2PF), but as the precision of the measurement increases, the detail smoothed out by the approximation becomes significant. We incorporate the fine radial structure of the density distribution from density functional theory calculations, focusing on the unevenness of the radial distribution rather than the half-height radius or skin depth differences. Using Monte Carlo Glauber simulation, we measure the effect of the fine radial structure on the eccentricity observables, and participant nucleon distributions. We report a difference on the order of 1% compared to the 2PF approximation. This indicates that the fine radial structure needs to be taken into account for high-precision modeling.