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arXiv · 1904.01225

$Ab~initio$ description of collectivity for $sd$ shell nuclei

A. Saxena·A. Kumar·V. Kumar·P. C. Srivastava·T. Suzuki
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Abstract

In the present work, we have reported shell model results for open shell nuclei Ne, Mg and Si isotopes with $10 \leq N \leq 20$ 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 $B(E2;2_1^+\rightarrow 0_1^+)$ 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.

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A. Saxena, A. Kumar, V. Kumar, P. C. Srivastava, T. Suzuki. 2019-04-02. $Ab~initio$ description of collectivity for $sd$ shell nuclei. https://doi.org/10.1007/s10751-019-1582-y

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