Space-time evolution of nuclear reactions probed by two-proton intensity interferometry.

Abstract

An approximate relation is derived which allows the calculation of the two-proton correlation function for any reaction model capable of predicting the classical single-particle phase-space distribution or Wigner function in the exit channel. The sensitivity of the calculated two-proton correlation functions to source radii and lifetimes is illustrated with simple parametrizations. More realistic calculations are presented for two different regimes of emission time scales: slow particle evaporation from equilibrated compound nuclei, as predicted from the Weisskopf formula, and fast nonequilibrium particle emission in intermediate-energy nucleus-nucleus collisions, as predicted from the Boltzmann-Uehling-Uhlenbeck transport equation.