Effective Λn potential from relativistic Brueckner-Hartree-Fock theory

The effective ΛN potentials are derived from one-boson-exchange hyperon-nucleon interaction such as Juelich potentials, Juelich94a (Jul94) and Juelich05 (Jul05), within the relativistic Brueckner-Hartree-Fock theory. The Jul94 effective ΛN potential UΛ (pΛ) with pΛ=0 is -27.63 MeV at the nuclear saturation density, which is in good agreement with the observed data, whereas for the Jul05 effective ΛN potential, UΛ is -47.85 MeV, which is bound more than the observed data. We then compare the effective ΛN potential energies obtained in nonrelativistic and relativistic frameworks. With the Λ momentum pΛ increasing, the relativistic effect becomes obvious and provides more repulsive contribution. We also derive the scalar and vector potentials of the Λ hyperon from the effective ΛN potential in the relativistic framework. With these potentials, the coupling constants between mesons and the Λ hyperon are determined for each density in the framework of relativistic mean-field theory. Finally, we calculate the Λ single-particle energies of hypernuclei with these density-dependent coupling constants in the relativistic mean-field theory. We find that the single Λ binding energies of Λ hypernuclei from OΛ16 to PbΛ208 by using the Jul94 potential compare well with the experimental data.