Nuclear Dynamics at the Particle Threshold

TL;DR

This paper discusses the microscopic modeling of pygmy resonances in nuclei, emphasizing the importance of multi-phonon degrees of freedom for understanding low-energy nuclear excitations and their role in nucleosynthesis.

Contribution

It introduces an extended density functional and QRPA approach with multi-phonon degrees of freedom to accurately describe pygmy resonances and nuclear excitations.

Findings

Multi-phonon response functions improve understanding of nuclear fine structure.

The approach successfully describes pygmy resonances linked to nuclear skin oscillations.

Application to s-process nucleosynthesis models enhances astrophysical predictions.

Abstract

Recently, new low-energy modes of excitation called pygmy resonances have been observed. Their distinct feature is the close connection to nuclear skin oscillations. A successful description of the pygmy resonances could be achieved in a microscopic theoretical approach which incorporates the density functional theory and QRPA formalism extended with multi-phonon degrees of freedom. The latter is found of crucial importance for the understanding of the fine structure of nuclear electric and magnetic excitations at low energies. Corresponding microscopic multi-phonon response functions are implemented in the studies of s-process of nucleosynthesis.