Resonance Criteria and theD21Diproton

Abstract

A relativistic three-body theory of the ($2^{+}$) $\mathrm{NN}\pi$ system was applied to calculate elastic and inelastic $\left({}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}\right)\mathrm{pp}$ scattering below 1 GeV. Although the amplitude satisfies all standard resonance criteria, it has no pole corresponding to a diproton resonance.