Effect of the tensor force in the exchange channel on the spin-orbit splitting in 23F in the Hartree-Fock framework

We study the spin-orbit splitting (ls splitting) for the proton d orbits in 23F in the Hartree-Fock framework with the tensor force in the exchange channel. 23F has one more proton around the neutron-rich nucleus 22O. A recent experiment indicates that the ls splitting for the proton d orbits in 23F is reduced from that in 17F. Our calculation shows that the ls splitting in 23F becomes smaller by a few MeV because of the tensor force. This effect comes from the interaction between the valence proton and occupied neutrons in the 0d5/2 orbit through the tensor force and makes the ls splitting in 23F close to the experimental data