Abstract
The extension to odd nuclei of the equation of motion phonon method (EMPM) is briefly outlined. It derives and solves iteratively a set of equations of motion which yield an orthonormal basis of states composed of an odd particle coupled to orthonormal multiphonon states, also generated within the EMPM, describing the excitations of a doubly magic core.
The basis so obtained is used to solve the eigenvalue problem in the full particle-phonon space. We have applied the method to the odd neighbors of O-16 using an optimized chiral potential in a space spanned by particle-core basis states which include up to three-phonons.
The calculations have shown that the multiphonon states enhance enormously the density of levels and compress the whole spectrum, consistently with the data. They also contribute substantially to improve the agreement with the experimental moments and transitions strengths.