Single pole dominance in short- and intermediate-range $NN$ interaction

Abstract

It is demonstrated that both elastic and inelastic $NN$ scattering at laboratory energies up to 600--800 MeV, at least in some partial waves characterized by a large inelasticity, can be described by a superposition of the conventional long-range one-pion exchange and a specific short-range interaction induced by the $s$-channel dibaryon exchange. For the $^3P_2$, $^1D_2$ and $^3F_3$ partial waves, the pole parameters giving the best fit of the real and imaginary parts of the $NN$ phase shifts are consistent with the parameters of the respective isovector dibaryon resonances found experimentally. In the $^1S_0$ channel, the suggested interaction gives two poles of the $S$-matrix -- the well-known singlet deuteron and an excited dibaryon. On the basis of the results presented, a conclusion is made about the nature of $NN$ interaction and its strong channel dependence.