Full nuclear field theory treatment of two-particle-one-hole-excitations

The nuclear field theory series is summed up to all orders of perturbation theory including only Tamm-Dancoff vertices for the case of two-particle-one-hole-excitations. It is found that the theory gives the same results as those provided by the shell-model method, but only if all possible basis states are included in the formalism. Applicability of the theory is discussed in a simple model

A shell-model calculation in terms of correlated subsystems

A method for solving the shell-model equations in terms of a basis which includes correlated subsystems is presented. It is shown that the method allows drastic truncations of the basis to be made. The corresponding calculations are easy to perform and can be carried out rapidly

Shell model in the complex energy plane and two-particle resonances

An implementation of the shell-model to the complex energy plane is presented. The representation used in the method consists of bound single-particle states, Gamow resonances and scattering waves on the complex energy plane. Two-particle resonances are evaluated and their structure in terms of the single-particle degreees of freedom are analysed. It is found that two-particle resonances are mainly built upon bound states and Gamow resonances, but the contribution of the scattering states is also important.Comment: 20 pages, 9 figures, submitted to Phys.Rev.

Systematics of proton emission

A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angular momentum of the outgoing proton. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.Comment: 4 pages, 3 figure

A nuclear field treatment of the 3-particle system outside closed-shell nuclei

The nuclear field treatment of the 3-particle system is carried out to all orders of perturbation theory but without including hole-excitations. It is shown that the theory properly corrects both the Pauli principle violations and the overcompleteness of the basis

Full nuclear field theory treatment of two-particle-one-hole-excitations

The nuclear field theory series is summed up to all orders of perturbation theory including only Tamm-Dancoff vertices for the case of two-particle-one-hole-excitations. It is found that the theory gives the same results as those provided by the shell-model method, but only if all possible basis states are included in the formalism. Applicability of the theory is discussed in a simple model.Pour décrire les excitations à 2 particules-1 trou, nous faisons la somme de tous les diagrammes de perturbation de la théorie du champ nucléaire en incluant seulement les sommets Tamm-Dancoff. I1 est montré que la théorie donne les mêmes résultats que ceux fournis par la méthode du modèle en couches, mais seulement si tous les états de base possibles sont introduits dans le formalisme. L'applicabilité de la théorie est discutée dans un modèle simple

Superfluid properties of the inner crust of neutron stars

PT