The quark model and the nature of the repulsive core of the nucleon-nucleon interaction

Abstract

The nature of the repulsive core of the nucleon-nucleon interaction is studied in the quark model. The resonating group equation for nucleon-nucleon scattering is solved with the colour Fermi-Breit interaction including further a linear or quadratic confinement potential. It is shown that the colour magnetic interaction which is adjusted to the Δ-nucleon mass splitting favours the [42] orbital symmetry and disfavours the completely symmetric orbital state [6]. For the important [42] orbital symmetry the relative S wave function between the two nucleons has to have a node. In the framework of the resonating group method including the NN, ΔΔ and the hidden colour (CC) channels it is shown that this node produces a 3S and 1S phase shift which is identical to a hard core phase shift with a hard core radius r 0 between 0.3 and 0.6 fm depending on the assumed root mean square radius of the quark part of the nucleon.