Date of Award

Winter 12-15-2015

Author's School

Graduate School of Arts and Sciences

Author's Department

Physics

Degree Name

Doctor of Philosophy (PhD)

Degree Type

Dissertation

Abstract

A fully nonlocal treatment for the dispersive optical model (DOM) is implemented for both the real and imaginary part of the self-energy inspired by ab initio theoretical calculations

of this quantity. By means of the dispersion relation between the real and imaginary part of the optical potential a link between the energy domain of nuclear

reactions and nuclear structure is

established. The relevant scattering data for neutrons and protons on $^{40}$Ca are described with the same quality as was accomplished with previous local versions of the DOM.

The solution of the Dyson equation at positive and negative energies

is generated with a complete treatment of the nonlocality of the potentials. The resulting propagator has been utilized to explain and predict relevant quantities

of the ground-state of the $^{40}$Ca nucleus. In particular the charge density, spectral strength and particle number can, for the first time, be accurately described.

Moreover, due to the introduction of nonlocality in the imaginary part

of the self-energy it is also possible to describe high-momentum protons and the contribution of the two-body interaction to the ground-state energy.

The calculation of the spectral density at positive energies allows for the determination of the spectral strength of mostly occupied single-particle orbits in the continuum.

Consistency of the resulting depletion numbers with the corresponding occupation numbers is studied and compared to ab initio calculations for these quantities.

Starting from the $^{40}$Ca self-energy, an extension to the $^{48}$Ca nucleus is implemented focusing on the $N-Z$ dependence of the nucleon self-energy.

Neutron scattering data can be described with even better quality than previous local DOM calculations. The scattering properties for protons are of similar excellent quality

as for previous local results. From the solution of the Dyson equation for neutrons it is possible to calculate the neutron distribution of this nucleus allowing

for the determination of the neutron skin which is relevant for the physics of neutron stars. The resulting value is larger than most calculations previously reported including

an ab initio one. An argument supporting a large neutron skin is provided by analyzing proton elastic scattering data on both $^{40}$Ca and $^{48}$Ca.

Language

English (en)

Chair and Committee

Willem H Dickhoff

Committee Members

Lee Sobotka, Robert Charity, Mark Alford, Demetrios Sarantites

Comments

Permanent URL: https://doi.org/10.7936/K7XK8CTT

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