Manifestation of Dynamically Unfavored Transitions in the Angular Distribution of Photogragments

Abstract

A class of parity-favored electric dipole transitions are classed as "dynamically unfavored" with a photoparticle angular distribution parameter $\beta \sim -1\mathrm{}$. This deviation from the elementary-model value $\beta =2\mathrm{}$ results when the squared pseudoscalar operator ${\left({\overrightarrow{j}}_t·\hat{r}\right)}^2$ is nonzero. Herrick's SO(4) classification singles out doubly excited ${}_{}{}^1{}_{}{}^{}P_{}^{\circ }{}_{}{}^{}$. continuum eigenchannels of ${\mathrm{H}}^{-}$ and He with ${\left({\overrightarrow{j}}_t·\hat{r}\right)}^2\sim 0 or \sim 1$. Most of the photoelectrons should have ${\left({\overrightarrow{j}}_t·\hat{r}\right)}^2\sim 1$, i.e., $\beta \sim -1\mathrm{}$.