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 $\gamma d\to pn$ in the photon energy range $E_{\gamma }=0-400$ MeV. Nine nucleon-nucleon $s$-channel partial amplitudes are reconstructed in the dispersion relation $N/D$ method: ${}^1{S}_0$, ${}^3{S}_1{-}^3{D}_1$, ${}^3{P}_0$, ${}^1{P}_1$, ${}^3{P}_1$, ${}^3{P}_2$, ${}^1{D}_2$, ${}^3{D}_2$ and ${}^3{F}_3$. Correspondingly, the dispersive representation of partial amplitudes $N\Delta \to pn$, $N{N}^{\ast }\to pn$ and $NN\pi \to pn$ is given. 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 $\gamma d\to N\Delta (1232)\to pn$, $\gamma d\to N{N}^{\ast }(1400)\to pn$ and $\gamma d\to NN\pi \to pn$. The $\gamma d\to pn$ partial amplitudes for nine above-mentioned channels are found. It is shown that the process $\gamma d\to pn\to pn$ is significant for the waves ${}^1{S}_0$, ${}^3{P}_0$, ${}^3{P}_1$, at $E_{\gamma }=50-100$ MeV, while $\gamma d\to N\Delta \to pn$ for the waves ${}^3{P}_2$, ${}^1{D}_2$,${}^3{F}_3$ dominates at $E_{\gamma }>300$ MeV. Meson exchange current contributions into the deuteron disintegration are estimated: they are significant at $E_{\gamma }=100-400$ MeV.

Comments: 22 pages, LaTeX, epsfig.sty, table