Five-body resonances in $^8$He and $^8$C using the complex scaling method

TL;DR

This paper investigates five-body resonances in $^8$He and $^8$C using the complex scaling method, revealing isospin-symmetry breaking effects and predicting resonance properties for future experiments.

Contribution

It introduces a five-body model for $^8$He and $^8$C, analyzing their resonances and isospin symmetry breaking with the complex scaling method, providing new theoretical predictions.

Findings

Four resonant states in $^8$He

All five states in $^8$C are resonances

Similar valence nucleon configurations in both nuclei

Abstract

We study many-body resonances in the neuron-rich $^8$He and the mirror proton-rich $^8$C using the $^4$He+$N$+$N$+$N$+$N$ five-body model with the isospin $T=2$ system. Resonances are described with the complex energy eigenvalues as the Gamow states using the complex scaling method. In $^8$He, we obtain five states, in which four states are resonances, and in $^8$C all five states are resonances.We discuss the isospin-symmetry breaking dynamically induced by the Coulomb interaction in the energy spectra and decay widths of the resonances in two mirror nuclei. We predict the resonance energies and decay widths for the future experiments. We also investigate the configurations of valence nucleons above $^4$He in two nuclei with the $jj$ coupling scheme and all the states dominantly have the $p$-shell configurations. From the configuration mixing, $^8$He and $^8$C give the similar results, which indicates the good symmetry in two nuclei.