2023/10/18 by N. Hizawa, Hizawa, N., K. Hagino +1
Physics and Astronomy · #Astronomical and nuclear sciences #Data Analysis #FOS: Physical sciences #Nuclear Physics and Applications #Nuclear Theory (nucl-th) #Nuclear physics research studies #Statistics and Probability (physics.data-an)
paper · doi:10.48550/arxiv.2310.11666
openalex publication_date 2023/10/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A microscopic description of nuclear fission represents one of the most challenging problems in nuclear theory. While phenomenological coordinates, such as multipole moments, have often been employed to describe fission, it is not obvious whether these parameters fully reflect the shape dynamics of interest. We here propose a novel method to extract collective coordinates, which are free from phenomenology, based on multi-task deep learning in conjunction with a density functional theory (DFT). To this end, we first introduce randomly generated external fields to a Skyrme-EDF and construct a set of nuclear number densities and binding energies for deformed states of 236U around the ground state. By training a neural network on such dataset with a combination of an autoencoder and supervised learning, we successfully identify a two-dimensional latent variables that accurately reproduce both the energies and the densities of the original Skyrme-EDF calculations, within a mean absolute error of 113 keV for the energies. In contrast, when multipole moments are used as latent variables for training in constructing the decoders, we find that the training data for the binding energies are reproduced only within 2 MeV. This implies that conventional multipole moments do not provide fully adequate variables for a shape dynamics of heavy nuclei.