Low-Energy Dipole Strength in $$^8$$He

Abstract

In this work, we present new ab initio coupled-cluster calculations of dipole-excited state properties of $$^8$$ 8 He based on the chiral effective field theory interaction 1.8/2.0 (EM). We focus on the dipole polarizability, and compare the results to our previous study [Phys. Rev. C 105, 034313 (2022)] and subsequent theoretical work. With the aim of connecting the presence of low-lying dipole strength to structure properties of $$^8$$ 8 He, we compute the point-neutron radius, finding excellent agreement with available experimental data, and investigate its correlation with the dipole polarizability.