Contribution of the rho meson and quark sub-structure to the nuclear spin-orbit potential

Abstract

The microscopic origin of the spin-orbit (SO) potential in terms of sub-baryonic degrees of freedom is explored and discussed for application to nuclei and hyper-nuclei. We thus develop a chiral relativistic approach where the coupling to the scalar- and vector-meson fields are controlled by the quark substructure. This approach suggests that the isoscalar and isovector density dependence of the SO potential can be used to test the microscopic ingredients which are implemented in the relativistic framework: the quark substructure of the nucleon in its ground-state and its coupling to the rich meson sector where the $\rho$ meson plays a crucial role. This is also in line with the Vector Dominance Model (VDM) phenomenology and the known magnetic properties of the nucleons. We explore predictions based on Hartree and Hartree-Fock mean field, as well as various scenarios for the $\rho$-nucleon coupling, ranked as weak, medium and strong, which impacts the isoscalar and isovector density dependence of the SO potential. We show that a medium to strong $\rho$ coupling is essential to reproduce Skyrme phenomenology in $N=Z$ nuclei as well as its isovector dependence. Assuming an SU(6) valence quark model our approach is extended to hyperons and furnishes a microscopic understanding of the quenching of the $N\Lambda$ spin-orbit potential in hyper-nuclei. It is also applied to other hyperons, such as $\Sigma$, $\Xi$ and $\Omega$.

9 pages, 3 tables

References in corpus (8)

• Shell Structure and $\rho$-Tensor Correlations in Density-Dependent Relativistic Hartree-Fock theory
• Evolution of Nuclear Shell Structure due to the Pion Exchange Potential
• Relativistic Chiral Hartree-Fock description of nuclear matter with constraints from nucleon structure and confinement
• QCD susceptibilities and nuclear matter saturation in a chiral theory: inclusion of pion loops
• Spin-orbit interaction in relativistic nuclear structure models
• Note on spin-orbit interactions in nuclei and hypernuclei
• In-medium chiral SU(3) dynamics and hypernuclear structure
• Scalar field in nuclear matter: the roles of spontaneous chiral symmetry breaking and nucleon structure

Cited by in corpus (3)

• Comparison of different relativistic models applied to dense nuclear matter
• Constituent quark axial current couplings to light vector mesons in the vacuum and with a weak magnetic field
• Ground State Properties of Charmed Hypernuclei with Mean Field Approach