Ab initio no-core shell model study of neutron-rich $^{18,19,20}$C isotopes

TL;DR

This study uses the ab initio no-core shell model with various nucleon-nucleon interactions to analyze the spectra, electromagnetic properties, and radii of neutron-rich carbon isotopes, comparing results with experimental data and shell model calculations.

Contribution

It applies the no-core shell model with multiple interactions to neutron-rich isotopes, providing insights into their structure and interaction sensitivities, and compares with shell model results.

Findings

INOY interaction yields better binding energy agreement with experiments.

B(E2) transition strengths are highly sensitive to the nuclear interaction.

Ground state energies and radii vary with NCSM parameters.

Abstract

We implement the ab initio no-core shell model approach to study neutron-rich $^{18}$C, $^{19}$C and $^{20}$C isotopes. For this purpose, we employ charge-dependent Bonn 2000 (CDB2K), inside non-local outside Yukawa (INOY) and chiral next-to-next-to-next-to-leading order (N$^{3}$LO) nucleon-nucleon interactions. Low-lying energy spectra, electromagnetic properties and point-proton radii for these nuclei up to basis space $N_{\rm max}$ = 4 are calculated. Binding energies obtained with INOY interaction are in better agreement with the experimental values as compared to other \textit{ab initio} interactions. We also show the behavior of ground state energy and point-proton radii with the NCSM parameters, $\hbar$$\Omega$ and $N_{\rm max}$. We report a strong sensitivity of the B(E2) values from the first excited $2^+$ to the ground state of $^{18}$C and $^{20}$C to the nuclear interaction. Shell model calculations with YSOX interaction are also performed, and corresponding results are compared with ab initio one.