Speaker
Description
The concept of nuclear pairing plays a central role in explaining a wide range of nuclear phenomena, including separation energies, the structure of low-lying spectra, and giant resonances. While most theoretical descriptions of pairing rely on phenomenological schematic models or energy density functional approaches, recent developments in chiral interactions open the path toward ab-initio calculations of open-shell nuclei within the Hartree–Fock–Bogoliubov (HFB) framework.
In this work, we present systematic calculations for selected isotopic chains, focusing on both ground- and excited-state properties of even–even nuclei. Our approach combines the spherically symmetric HFB framework with many-body perturbation theory corrections [2, 3], as well as the quasiparticle extensions of the Tamm–Dancoff approximation (QTDA) and the random-phase approximation (QRPA). All calculations are based on state-of-the-art ab-initio Hamiltonians derived from chiral effective field theory [3].
The primary objective of this benchmark study is to assess the predictive power and limitations of these methods, with particular emphasis on the description of excited states. Our results provide insight into the interplay between pairing correlations and many-body approximations, and highlight key challenges in further development of ab-initio description of nuclear excitations.
References:
[1] A. Tichai, R. Roth and T. Duguet T, Front. Phys. 8, 164 (2020), https://doi.org/10.3389/fphy.2020.00164.
[2] A. Scalesi et al., Eur. Phys. J. A 60, 209 (2024), https://doi.org/10.1140/epja/s10050-024-01424-1.
[3] T. Miyagi, Eur. Phys. J. A 59, 150 (2023), https://doi.org/10.1140/epja/s10050-023-01039-y.