Role of collectivity in intermediate-mass nuclei and alpha-capture reactions from the ab initio symmetry-adapted no-core shell model
Abstract: In this talk, I will discuss the emergence of collectivity from first principles in light and intermediate-mass nuclei, up to the calcium region, with implications for reproducing enhanced E2 transitions in deformed nuclei without effective charges, as well as for the description of alpha-capture reactions of interest to X-ray burst (XRB) nucleosynthesis. Structure calculations use the N2LOopt chiral potential and are based on the ab initio symmetry-adapted no-core shell model (SA-NCSM) that expands the reach of NCSM to heavier nuclei by exploiting approximate symmetries of nuclei. In particular, I will focus on collective features of Ne and Mg isotopes, as well as the alpha-capture reaction through the 1- resonance in Ne-20. The reaction rate is, in turn, provided as input to calculate the abundance pattern from XRB nucleosynthesis simulations, which is compared to results based on the present database for fixed astrophysical conditions.