Three-body Faddeev calculations for the low-lying states of O 18 in momentum space

Le résumé fourni par la source

In this paper, the $^{18}\mathrm{O}$ nucleus is studied by means of a three-body model consisting of an inert $^{16}\mathrm{O}$ core and two neutrons. For the three-body system, the Faddeev equations are solved directly in momentum space using the partial-wave decomposition. The momentum-space formulation usually requires the momentum representation $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{V}(|\mathbf{p}\ensuremath{-}{\mathbf{p}}^{\ensuremath{'}}|)$ of the two-body interaction $V(r)$ used. However, our method allows us to deal directly with any $V(r)$ in its original form in coordinate space, while avoiding the use of its representation in momentum space. In this way, we can then easily introduce the coordinate-space techniques, such as the supersymmetric transformation, to deal with the possible Pauli-blocking problem for the core-$n$ subsystem. For $^{18}\mathrm{O}$, the partial spectrum, including the ground state and several positive-parity low-lying excited states, is obtained, and the distribution of energy levels is consistent with previous work. For each state, the root-mean-square radius is calculated, and the structure is discussed in terms of partial-wave components. In addition, we performed some calculations on the $^{22}\mathrm{C}$ nucleus for further application. The results obtained are close to the most recent experimental values. Our momentum-space method can also be used to calculate the properties of other nuclei suitable for the three-body model.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.