Q2Q¯2 resonances in the baryon-antibaryon system

Two-quark-two-antiquark mesons which couple strongly to baryon-antibaryon channels are classified. The quantum numbers and masses of prominent states are predicted from the MIT bag model. The couplings of Q²Q¯² states to BB¯ are estimated using the ³P₀ model and peripherality. Though most Q²Q¯² states do not couple strongly to BB¯, many prominent resonances remain. Important Q²Q¯² resonances in the following processes are enumerated and discussed: elastic NN¯ scattering, NN¯-->π⁺π^-, NN¯ resonances at or below threshold, and exotic isotensor baryon-antibaryon resonances.