Hadronic Molecules and Scattering Amplitudes from the Nonrelativistic Quark Model

This report summarizes recent calculations of low-energy hadron-hadron scattering amplitudes in the nonrelativistic quark potential model, which assume that the scattering mechanism is a single interaction (usually OGE) followed by constituent interchange. We refer to the scattering diagrams as ``quark Born diagrams". For the cases chosen to isolate this mechanism, I=2 $\pi \pi$, I=3/2 K$\pi$, KN and NN, the results are usually in good agreement with experimental S-wave scattering amplitudes given standard potential-model parameters. These calculations also lead to predictions of vector-vector bound states, one of which may be the $\theta (1710)$. This assignment can be tested by searches for K$\bar{\mathrm{K}}\pi \pi$ and $\varphi {\pi }^0\gamma$ decay modes of the $\theta (1710)$.