Generalized Momentum Distribution of Infinite and Finite Nucleon Systems

The generalized momentum distribution n(vec p,vec Q), a Fourier transform of the half-diagonal two-body density matrix ρ _2h (vec r₁ ,vec r₂ ;vec r'₁ ) in the variables vec r₁ - vec r'₁ and vec r'₁ - vec r₂ is studied for nuclear systems. In the case of infinite nuclear matter, the calculation has been carried out within the Fermi hypernetted-chain procedure assuming Jastrow correlations, and the role of the short-range correlations has been revealed in certain kinematic domains. In the case of finite nuclei, the calculation of n(vec p,vec Q) for protons has been carried out, first within the independent-particle model, assuming a harmonic oscillator basis. Results for the closed shell nuclei ⁴He, ¹⁶O, ⁴⁰Ca are presented and are expected to be reliable in certain regions of the momenta vec p and vec Q, where the finite size and the Fermi statistics play the dominant role. Next, a calculation of n(vec p,vec Q) of protons for the nucleus ⁴He is presented, based on Jastrow correlations and the first two terms of a low-order cluster approximation. Work is in progress to study n(vec p,vec Q) of other nuclei incorporating the effect of short range correlations. The evaluation of n(vec p,vec Q) is useful for the study of the propagation mechanism of struck nucleons through the nuclear medium in various scattering processes, and for the understanding of elementary excitations of nuclei.