First Steps Toward the Ab Initio Description of Mid-Mass Open-Shell Nuclei
- Thomas Duguet, CEA/IRFU/SPhN
Wednesday, March 12, 4:10 PM - Nuclear Science Seminar
NSCL Lecture Hall
The challenging theoretical study of a quantum mesoscopic system such as the atomic nucleus is usually realized by combining two strategies, i.e. the most (yet doable) reductionist approach with a more effective level of description. This leads in low-energy nuclear theory to the formulation of ab initio quantum many-body methods on the one hand and of effective many-body approaches on the other hand. While the former provide a more fundamental perspective, the applicability domain of the latter is much more extended.
In the last ten years, several high-quality ab-initio many-body methods have been developed to address nuclei made of several tens of nucleons, recently achieving converged calculations with realistic two- and three-nucleon interactions. A pivotal work was the re-introduction of coupled cluster techniques to nuclear theory after a long period of intense development in quantum chemistry. Alongside, self-consistent Green's function theory and in-medium similarity renormalization group techniques have provided quantitatively analogous results, opening new paths to mid-mass nuclei. Although impressive, these developments were limited until very recently to doubly closed-shell nuclei, plus those accessible in their immediate vicinity via the addition and the removal of 1 or 2 nucleons. These systems eventually represent a very limited fraction of the nuclei at play in problems of current interest and of the nuclei to be studied with the upcoming generation of nuclear radioactive ion beam facilities.
In this context, I will discuss the extension of these many-body methods to genuinely (singly) open-shell systems that is now being undertaken and that opens up the ab-initio description of several hundred mid-mass nuclei for the first time.