Precise comparison of the Gaussian expansion method and the Gamow shell model

Abstract

We perform a detailed comparison of results of the Gamow Shell Model (GSM) and the Gaussian Expansion Method (GEM) supplemented by the complex scaling (CS) method for the same translationally-invariant cluster-orbital shell model (COSM) Hamiltonian. As a benchmark test, we calculate the ground state $0^{+}$ and the first excited state $2^{+}$ of mirror nuclei ${}^6$He and ${}^6$Be in the model space consisting of two valence nucleons in $p$-shell outside of a ${}^4$He core. We find a good overall agreement of results obtained in these two different approaches, also for many-body resonances.

Comments: 8 pages, 7 figures. Submitted to PRC