Single-particle properties and short-range correlations in nuclear matter

Ladder correlations are studied with inclusion of hole-hole propagation to all orders. The resulting effective interaction is separated into a forward-going and a backward-going contribution with the numerical use of dispersion relations. This procedure allows the correct calculation of the corresponding self-energy terms. Self-consistency between the ladders and the self-energy is established for the quasi-particle energy. Calculations are performed with semi-realistic interactions derived from Reid's soft-core interaction to avoid the appearance of pairing instabilities. A careful study of the complete momentum and energy dependence of the resulting self-energy is made for various densities. Effective mass contributions are studied coming from both the k- and ω-dependence of the self-energy. Accurate calculation of all relevant spectral functions is performed with proper fulfillment of the sum rule and quasi-particle properties are discussed. An important fraction of the single-particle strength is found at very high energy due to the realistic short-range repulsion in the interaction. From the hole spectral function the momentum distribution is calculated at various densities. The depletion due to the influence of short-range correlations around normal nuclear matter density amounts to about 13%. (orig.)