【科技日报】科研人员首次在实验中观测到新核素铝-20

Core Insights - The research team from the Institute of Modern Physics of the Chinese Academy of Sciences has made significant progress in the study of rare decay modes of atomic nuclei, successfully observing the new nuclide aluminum-20 and its decay through a rare three-proton emission mode [1][2] Group 1: Research Findings - Over 3,300 nuclides have been discovered, with fewer than 300 being stable nuclides found in nature; the rest are unstable and undergo radioactive decay [1] - The study utilized the fragment separator at the Helmholtz Institute and employed in-flight decay experimental techniques to measure the angular correlations of decay products from aluminum-20 [2] - Aluminum-20 is the lightest aluminum isotope discovered experimentally, located outside the proton drip line and lacking seven neutrons compared to stable aluminum isotopes [2] Group 2: Theoretical Implications - The research team applied the Gamow shell model and Gamow coupling method for theoretical calculations, successfully reproducing the measured decay energy of aluminum-20 and predicting its ground state spin-parity [2] - The study explored the isospin symmetry between aluminum-20 and its mirror nucleus nitrogen-20, revealing a breaking of this symmetry, which is significant for nuclear structure research [2]