Non-strange four quark systems

Using a Coulombic one gluon exchange interaction, and a generalisation of a linear confining potential to multiquark systems, the four body Schrodinger equation is solved, using potential parameters and effective quark masses obtained from a previous fit to the baryon spectrum. Masses of non-strange four states are predicted, and their decay properties considered. Good agreement is obtained between the predicted properties ofT-diquonium states and observed resonances coupled toB B channels, but it is found thatM-diquonia have a strong tendency to decay into multimeson final states. Alternative possibilities for narrow four quark states are considered.