Nuclear giant resonances from first principles

TL;DR

This paper reviews ab initio methods for studying nuclear giant resonances, comparing various many-body approaches grounded in realistic nuclear interactions and their predictions for benchmark nuclei.

Contribution

It provides a comprehensive survey of modern first-principles theoretical frameworks and computational techniques for nuclear giant resonances, highlighting their differences and similarities.

Findings

Comparison of theoretical predictions for $^{16}$O and $^{40}$Ca

Analysis of agreement and divergence among methods

Connection of models to experimental observables

Abstract

This chapter presents an ab initio perspective on giant resonances in atomic nuclei and surveys the principal theoretical frameworks that aim to describe these collective excitations from first principles. While the study of nuclear giant resonances has traditionally been dominated by the energy density functional approach, recent years have witnessed the development of advanced many-body approaches grounded directly in realistic nuclear interactions, namely, Hamiltonians that reproduce nucleon-nucleon phase shifts and accurately describe the binding energies of light nuclei. Within this modern framework, we review the main many-body methods currently used to compute nuclear response functions. These include the random phase approximation, the Lorentz integral transform coupled-cluster theory, the projected generator-coordinate method, and the self-consistent Green's functions approach. After giving a general conceptual and historical overview of giant-resonance phenomena, we outline the theoretical foundations and computational implementations of each method. We conclude with a critical comparison of their predictions for selected benchmark nuclei, $^{16}$O and $^{40}$Ca, emphasizing points of agreement and divergence, while maintaining a close connection to the relevant experimental observables.