Pauli-blocking in the quasideuteron model of photoabsorption

Abstract

We calculate the effects of Pauli-blocking in the quasideuteron model of hard photon absorption. Our approach is based upon phase-space considerations and uses Fermi-gas state densities that conserve linear momentum. The Pauli-blocking function that we obtain differs from Levinger's phenomenological exponential factor and yields nuclear photoabsorption cross sections that are in good agreement with experimental data for photon energies up to the pion threshold. The temperature dependence of the nuclear photoabsorption cross section in the quasideuteron regime is also investigated. The model that we use to describe nuclear photoabsorption is particularly suited for application to preequilibrium models of hard photon emission.