Low- and intermediate-energy nucleon-nucleon interactions and the analysis of deuteron photodisintegration within the dispersion relation technique

Abstract

The nucleon-nucleon interaction in the region of the nucleon kinetic energy up to 1000 MeV is analysed together with the reaction $γd \to pn$ in the photon energy range $E_γ=0-400$ MeV. Nine nucleon-nucleon $s$-channel partial amplitudes are reconstructed in the dispersion relation $N/D$ method: $^1S_0$, $^3S_1-^3D_1$, $^3P_0$, $^1P_1$, $^3P_1$, $^3P_2$, $^1D_2$, $^3D_2$ and $^3F_3$. Correspondingly, the dispersive representation of partial amplitudes $NΔ\to pn$, $NN^* \to pn$ and $NNπ\to pn$ is given. Basing on that, we have performed parameter-free calculation of the amplitude $γd \to pn$, taking into account: $(i)$ pole diagram, $(ii)$ nucleon-nucleon final-state rescattering $γd \to pn \to pn$, and $(iii)$ inelastic final-state rescatterings $γd \to NΔ(1232) \to pn$, $γd \to NN^*(1400) \to pn$ and $γd \to NNπ\to pn$. The $γd \to pn$ partial amplitudes for nine above-mentioned channels are found. It is shown that the process $γd \to pn \to pn$ is significant for the waves $^1S_0$, $^3P_0$, $^3P_1$, at $E_γ =50 -100$ MeV, while $γd \to NΔ\to pn$ for the waves $^3P_2$, $^1D_2$,$^3F_3$ dominates at $E_γ > 300$ MeV. Meson exchange current contributions into the deuteron disintegration are estimated: they are significant at $E_γ=100-400$ MeV.