STUDY OF NΔ AND ΔΔ RESONANCE STATES IN CONSTITUENT QUARK MODELS

To look for nonstrange dibaryon resonances, a systematic calculation of nucleon–nucleon scattering phase shifts of two interacting baryon clusters of quarks with explicit coupling to NΔ and ΔΔ states is done. Two phenomenological nonrelativistic quark models giving similar low-energy NN properties are found to give significantly different dibaryon resonance structures. In the chiral quark model, the dibaryon system does not resonate in the NNS waves. In the quark delocalization color screening model, the S wave NN resonances appear with nucleon size b = 0.6. There is a IJ = 12NΔ resonance state in the [Formula: see text] scattering phase shifts at 2168 MeV in this model. Both quark models give an IJ = 03 ΔΔ resonance, which is a promising candidate for the explanation of the ABC structure at ~ 2.36 GeV in the production cross section of the reaction pn → dππ by the CELSIUS-WASA collaboration. None of the quark models used has any bound NΔP states that might generate odd-parity resonances.