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

Nucleon-nucleon interactions in the region of the nucleon kinetic energies up to $1000$ MeV are analysed together with the reaction $\gamma d \to pn$ in the photon energy range up to $E_{\gamma}=400$ MeV. The following 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 $N\Delta \to pn$, $NN^* \to pn$ and $NN\pi \to pn$ is given and parameters which determine these two baryon amplitudes are found. Basing on that, we have performed parameter-free calculation of the amplitude $\gamma d \to pn$, taking into account: $(i)$ pole diagram, $(ii)$ nucleon-nucleon final-state rescattering $\gamma d \to pn \to pn$, and $(iii)$ inelastic final-state rescatterings $\gamma d \to N\Delta(1232)$ $ \to pn$, $\gamma d \to NN^*(1400) \to pn$ and $\gamma d \to NN\pi \to pn$. The $\gamma d \to pn$ partial amplitudes for the above-mentioned channels are found. It is shown that the process $\gamma d \to pn \to pn$ is significant for the waves $^1S_0$, $^3P_0$, $^3P_1$, at $E_{\gamma} =50 -100$ MeV, while $\gamma d \to N\Delta \to pn$ dominates for the waves $^3P_2$, $^1D_2$, $^3F_3$ at $E_{\gamma} > 300$ MeV. Meson exchange current contributions into the deuteron disintegration are estimated: they are significant at $E_\gamma =100-400$ MeV