2024/02/20 by Anna E. McCoy, McCoy, Anna E., M. A. Caprio +5 · 3 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Geology and Paleoclimatology Research #Nuclear Theory (nucl-th) #Nuclear physics research studies
paper · pdf · doi:10.48550/arxiv.2402.12606
openalex publication_date 2024/02/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
The spectrum of 12Be exhibits exotic features, e.g., an intruder ground state and shape coexistence, normally associated with the breakdown of a shell closure. While previous phenomenological treatments indicated the ground state has substantial contributions from intruder configurations, it is only with advances in computational abilities and improved interactions that this intruder mixing is observed in ab initio no-core shell model (NCSM) predictions. In this work, we extract electromagnetic observables and symmetry decompositions from the NCSM wave functions to demonstrate that the low-lying positive parity spectrum can be explained in terms of mixing of rotational bands with very different intrinsic structure coexisting within the low-lying spectrum. These observed bands exhibit an approximate SU(3) symmetry and are qualitatively consistent with Elliott model predictions.