Possibility of narrow resonances in nucleon-nucleon channels
  Compound states manifest themselves as bound states, resonances, or primitives, and their character is determined by their interaction with the continuum. If the interaction experiences a perturbation, a compound state can change its manifestation. Phase analysis of nucleon-nucleon scattering indicates the existence of primitives in the 3S1, 1S0, and 3P0 channels. Electromagnetic interaction can shift primitives from the unitary cut, turning them into narrow resonances. We evaluate this effect on the 1S0 proton-proton scattering channel within the framework of the Simonov-Dyson model. We show that electromagnetic interaction turns a primitve with a mass of 2000 MeV into a dibaryon resonance of approximately the same mass and a width of 260 keV. Narrow resonances of a similar nature may occur in other nucleon-nucleon channels. Experimental confirmation of the existence of narrow resonances would have important implications for the theory of nucleon-nucleon interaction. 
M. I. Krivoruchenko
nucl-th hep-ph