Classical model for two-proton correlations in intermediate-energy heavy-ion reactions

The Coulomb interaction between two protons sequentially evaporated from the same compound nucleus is studied as a possible origin for their measured correlations. This is done in the frame of three-body trajectory calculations with both Coulomb and nuclear forces. The temperature and mass of the emitting nucleus were determined from the measured energy spectra of single protons. The correlation function was found to be very sensitive to the mean time delay between the emissions of the two particles. A value ${\mathrm{\tau }}_0$=(1.0±0.2)×${10}^{\mathrm{-}21}$ s was obtained by comparison of our calculations with the two-proton correlation function measured at backward angles in the reaction ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ ${+}^{108}$Ag at 44 MeV/nucleon.