Ab initio description of collectivity for sd shell nuclei

Abstract

In the present work, we have reported shell model results for open shell nuclei Ne, Mg and Si isotopes with 10 ≤ N ≤ 20 in sd-shell model space. We have performed calculations in sd shell with two ab initio approaches: in-medium similarity renormalization group (IM-SRG) and coupled-cluster (CC) theory. We have also performed calculations with phenomenological USDB interaction and chiral effective field theory based CEFT interaction. The results for rotational spectra and B(E2;21+→01+) transitions are reported for even-mass isotopes. The IM-SRG and CC results are in reasonable agreement with the experimental data except at N = 20. This demonstrates a validity of ab initio description of deformation for doubly open-shell nuclei for sd shell. To see the importance of pf orbitals, we have also compared our results with SDPF-MU interaction by taking account of 2p − 2h and 4p − 4h configurations in sd-pf -shell model space. © 2019, Springer Nature Switzerland AG.