Ab initio investigations of A=8 nuclei: α–α scattering, deformation in 8He, radiative capture of protons on 7Be and 7Li and the X17 boson

Abstract

We apply the No-Core Shell Model with Continuum (NCSMC) that is capable of describing both bound and unbound states in light nuclei in a unified way with chiral two- and three-nucleon interactions as the only input. The NCSMC can predict structure and dynamics of light nuclei and, by comparing to available experimental data, test the quality of chiral nuclear forces. We discuss applications of NCSMC to the α–α scattering and the structure of 8Be, the p+7Be and p+7Li radiative capture and the production of the hypothetical X17 boson claimed in ATOMKI experiments. The 7Be(p, γ)8B reaction plays a role in Solar nucleosynthesis and Solar neutrino physics and has been subject of numerous experimental investigations. We also highlight our investigation of the neutron rich exotic 8He that has been recently studied experimentally at TRIUMF with an unexpected deformation reported.