Nucleon-nucleon interaction with a flip-flop model for quark confinement

Abstract

The nucleon-nucleon interaction with a flip-flop confining interaction which is free from the pathology of the color van der Waals force is studied in the framework of the quark cluster model supplemented by an effective meson-exchange potential (EMEP). The experimental phase shifts for spin-singlet states ( 1S 0, 1P 1, 1D 2) are well reproduced. The spin-orbit interaction from the confinement potential is also studied and compared with the one from the one-gluon exchange potential (OGEP). The strength of the former is determined so that it cancels the latter in the excited states of a nucleon. The cancellation does not occur in the NN interaction and the resulting spin-orbit force including both contributions has roughly the required strength for the 3P and 3D channels. This fact suggests the possibility that the substantial part of the NN spin-orbit force can be attributed to the quark contribution.