Probing toroidal density distributions with two-proton correlation functions?

Abstract

Transport calculations based on the Boltzmann-Uehling-Uhlenbeck (BUU) equation predict the formation of toroidal density distributions for central $^{36}\mathrm{Ar}$${+}^{45}$Sc collisions at E/A=80 MeV. Calculations with the Koonin-Pratt formalism are performed to explore whether the occurrence of such nonspherical breakup configurations could be tested via two-proton correlation measurements. The predicted signal appears detectable, but weak, because most protons emerge early in the reaction when the source is more compact. Contributions from nonzero impact parameters give rise to additional complications.