Proton-Proton Correlations In Ar-40+Au-197 Reactions And The Role Of The 2-Particle Phase-Space

Proton-proton correlations at small relative momenta were measured for Ar-40+Au-197 reactions at E/A = 200 MeV. Comparing the correlation functions to predictions based on single-particle phase space distributions from microscopic Boltzmann-Uehling-Uhlenbeck and quantum-molecular-dynamics (QMD) simulations, no satisfactory agreement could be established. Calculations utilizing two-particle emission probabilities predicted by the QMD model differ significantly from the single-particle calculations and are much closer to the experimental observations at E/A = 200 MeV, potentially signaling the importance of the two-particle density for the proton-proton correlation function.