Spin-Polarized Photoelectrons from Randomly Oriented Halogen Molecules by Unpolarized Radiation

Molecular photoelectrons have been observed to be spin polarized even if ejected from a beam of randomly oriented molecules by unpolarized radiation. The polarization and the asymmetry parameter $\beta$ for ${\mathrm{Br}}_2$, ${\mathrm{I}}_2$, C${\mathrm{H}}_3$Br, and C${\mathrm{H}}_3$I are compared with general predictions of a nonrelativistic model. While all available data of the differential cross section agree with this prediction, spin-polarization results partly disagree, manifesting the influence of the spin-orbit interaction upon the phases of molecular continuum wave functions.