2026/08/02 by Baoshan Xi, Pei Li, Chunjian Zhang +3
Physics and Astronomy · #nucl-th #nucl-ex
8 Pages 2 Figures; Comments are welcome
arxiv created 2026/08/02 · arxiv updated 2026/08/04
Short-range nucleon-nucleon correlations are a defining feature of the nuclear many-body wave function, yet they are invisible in the one-body density and therefore inaccessible to observables that measure a nuclear size. We show that proton-proton femtoscopy supplies the missing sub-femtometer sensitivity. In 16O+16O collisions at \rm √sNN= 200 GeV, we compare three nuclear-structure inputs spanning mean-field, low-resolution cluster, and short-range-correlated descriptions. The p-p correlation function separates all three, most sharply in peripheral collisions, where the ab initio input suppresses the extracted source radius by ∼5% relative to the mean-field baseline. Under identical conditions π+-π+ correlations respond an order of magnitude more weakly, and the Cpp/Cπ+π+ double ratio retains the full effect, pointing to the short-distance weighting of the 1S0 pair rather than to an overall rescaling of the source. The signal survives the leading theoretical systematic, the choice of strong-interaction potential, which we quantify explicitly. These results identify p-p femtoscopy as a short-distance-resolved probe of light-nucleus structure, complementary to flow observables that constrain only the low-order moments of the initial geometry.