NN and Nd Scattering with Intermediate Dibaryons

Abstract

Excitation of intermediate dibaryon resonances in hadronic processes accompanied by high momentum transfers is considered. It is shown that some basic features of NN inelastic scattering with single- or double-pion production can be effectively described by taking into account the short-range s-channel dibaryon excitation along with peripheral t-channel meson-exchange processes. In particular, isovector dibaryons with \(I(J^P)=1(2^+)\), \(1(3^-)\) and \(1(2^-)\) are shown to play an important role in reproducing the cross sections and especially polarization observables in the basic single-pion production reaction \(pp \rightarrow d\pi ^+\), while an isoscalar \(I(J^P)=0(3^+)\) dibaryon is crucial for describing the basic double-pion production process \(pn \rightarrow d (\pi \pi )_0\). Possible generalization of resonance (dibaryon) mechanisms considered in NN scattering to Nd elastic and inelastic scattering is also discussed.