Ab initio optical potentials and nucleon scattering on medium mass nuclei

Abstract

We derive ab initio optical potentials from self-consistent Green's function (SCGF) theory and compute the elastic scattering of neutrons off oxygen and calcium isotopes. The comparison with scattering data is satisfactory at low scattering energies. The method is benchmarked against nocore shell model with continuum (NCSMC) calculations, showing that virtual excitations of the target are crucial to predict proper fragmentation and absorption at higher energies. This is a significant step toward deriving optical potentials for medium mass nuclei and complex many-body systems in general.

Towards microscopic optical potentials in deformed nuclei

“…| the matrix elements of the creation and annhilation operators define the components of the numerator of the Green's function and are called the spectroscopic amplitudes S J . Together with the energy of the states, S J are the elements needed to construct the Green's functions (3). From the Green's functions the optical potential can be derived inverting the Dyson equation Σ = G −1 0 − G −1 , with G 0 the unperturbed Green's function propagator corresponding to H 0 [1].…”

“…therein for context regarding the importance of a consistent description of nuclear structure and reactions. Despite efforts and progress in later years in developing optical potentials from first principles using Green's function based methods [3][4][5][6] or multi-scattering [7][8][9] approaches, it is especially difficult to develop microscopic potentials for deformed nuclei. The description of deformed nuclei imposes an additional complexity to the calculation and formalism.…”

Exact scattering waves off nonlocal potentials under Coulomb interaction within Schrödinger's integro-differential equation

“…In the presence of a nonlocal potential Schrödinger's equation for scattering waves becomes integrodifferential. Explicit treatments of nonlocalities in Schrödinger's equation is an issue that has captured increasing interest from the stand point of ab-initio theories and models, specially aiming to global approaches for structure and reactions [1,2,3]. Therefore, robust methods able to provide solutions to the wave equation for any kind of kernel become imperative to accurately treat and assess model-independent nonlocalities of nuclear interactions.…”