Ab-initio No-Core Gamow Shell Model calculations with realistic interactions

Abstract

No-Core Gamow Shell Model (NCGSM) is applied for the first time to study selected well-bound and unbound states of helium isotopes. This model is formulated on the complex energy plane and, by using a complete Berggren ensemble, treats bound, resonant, and scattering states on equal footing. We use the Density Matrix Renormalization Group method to solve the many-body Schrödinger equation. To test the validity of our approach, we benchmarked the NCGSM results against Faddeev and Faddeev-Yakubovsky exact calculations for ${}^3$H and ${}^4$He nuclei. We also performed {\textit ab initio} NCGSM calculations for the unstable nucleus ${}^5$He and determined the ground state energy and decay width, starting from a realistic N${}^3$LO chiral interaction.

Comments: 17 pages, 14 figures. Revised version. Discussion on microscopic overlap functions, SFs and ANCs is added. Added references. Accepted for publication at PRC