Systematics ofQ¯q4systems with a pure chromomagnetic interaction

In the framework of a pure chromomagnetic Hamiltonian, we study all the states of $\overline{Q}{q}^4$ systems allowed by the Pauli principle. The wave functions are analyzed by group-theoretical techniques in a first step where the antiquark has an infinite mass and the quarks belong to an $\mathrm{SU}{\mathrm{}\left(3\right)\mathrm{}}_F$ multiplet. The breaking of these symmetries is performed exactly through two parameters $\eta$ and $\delta$. The emphasis is put on the corresponding energies relative to the physical thresholds in $\overline{Q}q+q^3$. We propose a number of new multiquarks which could be stable under strong interactions.