Polarization effect on the spin symmetry for anti-Lambda spectrum in ¹⁶O+Λ̄ system

The polarization effect on the spin symmetry for anti-Lambda spectrum in ¹⁶O+Λ̄ system has been studied in relativistic mean-field theory. The PK1 effective interaction is used for nucleon-meson couplings and G-parity symmetry with a reduction factor ξ= 0.3 is adopted for anti-Lambda-meson couplings. The energy differences between spin doublets in the anti-Lambda spectrum are around 0.10-0.73 MeV for pΛ̄ state. The dominant components of the Dirac spinor for the anti-Lambda spin doublets are found to be near identical. It indicates that the spin symmetry is still well-conserved against the polarization effect from the valence antiLambda hyperon, which leads to a highly compressed cold nucleus with the central density up to 2 -3 times of saturated density.