  Effects of the spin orbit-force on hadronic systems with strangeness or charm
are investigated by a valence quark model with the instanton-induced
interaction. By introducing this interaction, the spin-orbit splittings in the
negative-parity hyperons becomes 0.14 -- 0.37 times smaller. The flavor-octet
baryon mass spectrum and the splittings in the charmed baryons become
consistent with the experiments. Though the splitting is also reduced in the
flavor-singlet baryons, it still gives two third of the experimental value. The
reduction comes from the cancellation between the one-gluon exchange and the
instanton-induced interaction, which is channel-specific. In most of the
two-baryon channels, the symmetric and antisymmetric spin-orbit force of the YN
interaction remains strong after introducing this instanton effect. A few
exceptional channels, however, are found where the cancellation affects
strongly and the spin-orbit force becomes small.
