Structure of neutron-rich nuclei from the view point of few-body problems

• Grant number: 23/15738-7
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: April 12, 2024
• End date: May 11, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - Nuclear Physics
• Principal Investigator: Tobias Frederico
• Grantee: Tobias Frederico
• Visiting researcher: Emiko Hiyama
• Visiting researcher institution: Tohoku University/Tu, Japan
• Host Institution: Divisão de Ciências Fundamentais (IEF). Instituto Tecnológico de Aeronáutica (ITA). Ministério da Defesa (Brasil). São José dos Campos , SP, Brazil
• Associated research grant: 19/07767-1 - Nuclear reactions with weakly-bound or cluster-structured radioactive and stable nuclei, AP.TEM

Abstract

The study of the Boron neutron rich nuclei, 21B and 19B, described by a core and a cloud of four neutrons, namely, 21B=17B+n+n+n+n and 19B=15B+n+n+n+n, respectively, is challenging from both the physical and computational points of view. It is puzzling how the four-neutron halo organizes around the core to form stable or resonant states. As a building block, the 21B contains the 17B+n subsystem, where the effective interaction is known and was parametrized to produce a large negative scattering length, while it has a repulsive short-range part to avoid the halo neutrons to penetrate in the core region. In the case of 19B as a 15B+n+n+n+n system, it is necessary to build the 15B+n potential, which, in principle, will be constructed similarly to the 17B+n effective interaction in order to represent the known 16B low-lying states decaying to 15B+n. Our proposal to theoretically study both 21B and 19B as a four neutron halo system, requires the solution of the quantum five-body problem for bound/resonant state, which will be performed by using the Gaussian Expansion Method and complex scaling. (AU)