Photodisintegration of the Deuteron

The electric dipole cross section for $\gamma (d, p)n$ is examined, assuming no forces in ${}_{}{}^3{}_{}{}^{}P$ states. The nonvanishing $D$-state probability $P_D$ of deuteron gives rise to the isotropic part $a_e$ in angular distribution of the photoproton: $\frac{d\sigma }{d\omega }=a_e+b_e{sin}^2\theta$. It turns out, however, that the resulting value for $a_e$ is still small to explain the experimental cross section, even if $P_D$ is as large as 8 percent.