Quark bags and theNNinteraction

The $\mathrm{NN}$ phase shifts can be nicely parametrized with a $P$ matrix with matching radius $b\approx 6.0 \mathrm{Ge}{\mathrm{V}}^{-1\mathrm{}}\approx 1.2$ fm. For the interaction outside this radius a one-pion-exchange potential is used. For the $(I, J^P)=(0, 1^{+})$ six-quark system a detailed analysis of the $P$-matrix pole is made. The pole position and the bag-model prediction are in reasonably good agreement. The residue to the $\mathrm{NN}$ channel, however, is a factor of 5 larger than the bag prediction. A possible explanation is that in a six-quark bag there are strong color-singlet correlations. This is demonstrated in a simple model.