Two-nucleon spectral function of ¹⁶O at high momenta

A procedure for the calculation of the two-body spectral function of a finite nucleus is presented. This spectral function is used to calculate the longitudinal part of the ¹⁶O(e,e′ pp) cross section assuming plane waves for the outgoing nucleons. Short-range correlation effects are included in the pair-removal amplitudes by adding corresponding defect wave functions that are obtained from the solution of the Bethe-Goldstone equation in the finite nucleus. The associated G matrix is used as the effective interaction in a large but finite model space to calculate the pair-removal amplitudes in a random-phase approach. The resulting spectral functions exhibit clear differences between different realistic interactions in the momentum range 2-5 fm^-1 for the initial proton momenta.