Continuum excitations of O 26 in a three-body model: 0+ and 2+ states

The structure and decay dynamics for 0+ and 2+ continuum excitations of O26 are investigated in a three-body O24+n+n model. The validity of a simple approximation for the cross section profile for long-lived 2n emission is demonstrated. A sequence of three 0+ monopole ("breathing mode" type) excited states is predicted. These states could probably be interpreted as analogs of Efimov states pushed in the continuum due to insufficient binding. The calculated energies of the 2+ states are related to the excitation spectrum of O25. We discuss the correlation between the predicted O26 spectrum and experimental observations.