Single-particle spin–orbit strengths of the nucleon and hyperons by SU6 quark-model Original Research Article

The quark-model hyperon–nucleon interaction suggests an important antisymmetric spin–orbit component. It is generated from a color analogue of the Fermi–Breit interaction dominating in the one-gluon exchange process between quarks. We discuss the strength View the MathML source of the single-particle spin–orbit potential, following the Scheerbaumʹs prescription. Using the View the MathML source quark-model baryon–baryon interaction which was recently developed by the Kyoto–Niigata group, we calculate NN, ΛN and ΣNG-matrices in symmetric nuclear matter and apply them to estimate the strength View the MathML source. The ratio of View the MathML source to the nucleon strength View the MathML source is View the MathML source and View the MathML source in the Born approximation. The G-matrix calculation of the model FSS modifies View the MathML source to View the MathML source. For View the MathML source and View the MathML source, the effect of the short-range correlation is comparatively weak against meson-exchange potentials with a short-range repulsive core. The significant reduction of the Λ single-particle potential arises from the combined effect of the antisymmetric LS force, the flavor-symmetry breaking originating from the strange to up-down quark-mass difference, as well as the effect of the short-range correlation. The density dependence of View the MathML source is also examined.