B02“Elucidation of the forces between baryons through the collaboration of scattering  experiments and lattice QCD, and its application to hypernuclei“

B02 “Elucidation of the forces between baryons through the collaboration of scattering  experiments and lattice QCD, and its application to hypernuclei “

In the study of finite quantum many-body systems, if the interactions between particles are known, the structure and dynamics of the system can be accurately understood by rigorously solving the fundamental equation, the Schrödinger equation. This is also true for the study of quantum many-body systems that consist of hyperons (baryons containing strange quarks). In particular, Λ hyperons form nuclei called Λ hypernuclei, and are important particles that are also closely related to the structure deep inside neutron stars. However, the interaction between Λ hyperon and nucleon (ΛN interaction) is still largely uncertain, and the microscopic understanding of the many-body force (ΛNN 3-body force) that appears in Λ hypernuclei and the internal structure of neutron stars remain unsolved issues. In the B02 group, we aim to construct ΛN, ΣN interactions that enables quantitative discussion by promoting (1) measurement of the differential cross section of Λ hyperon and proton, (2) determination of the strength of the coupling between Λ and Σ by measuring the cusp that appears at the threshold for the production of Σ hyperon, and (3) derivation of the ΛN, ΣN potential by lattice QCD calculations. We provide this interaction as inputs for the precision calculations of Λ hypernuclei by the theory group (Group A).  This calculation results will be verified by (4) high-resolution spectroscopy of Λ hypernuclei. By developing precise calculations of Λ hypernuclei based on the interactions constructed by the B02 group, we will build a foundation for elucidating the ΛNN three-body force, which is the key to the repulsion of Λ in neutron stars.