Abstract
Resonance states of and have been studied using microscopic and three-cluster models, respectively. The resonance positions are localized by the three-body complex scaling method. An effective nucleon-nucleon interaction, which reproduces the low energy phase shifts and the energies of the ground and first excited states of with the three-cluster model, is used to calculate resonance states of and This model can reasonably reproduce the experimental and phase shifts at low energies. It gives a broad resonance as the ground state in and and in addition it gives two excited resonance states of and The resonance parameters of the state of in the present model are close to those deduced from their recent experimental data by Korsheninnikov et al. The same effective nucleon-nucleon interaction is used for a tentative investigation in order to explore the possibility of a tetra-neutron resonance by means of the four-body complex scaling method on a restricted set of model configurations. Our model does not give any evidence for a tetraneutron resonance.
- Received 19 May 2003
DOI:https://doi.org/10.1103/PhysRevC.68.034303
©2003 American Physical Society