title: Quantifying relativistic interactions from angular momentum partitioning measurements during photoionization.
abstract: We have measured the degree of helicity of fluorescent radiation from Ar+[3p4[3P]4p] 2P(o)1/2 formed by circularly polarized synchrotron radiation in the region of double excitations converging to Ar+3p4 nl satellite states. Angular momentum coupling allows the partitioning of the one unit of angular momentum brought into the system to be demarcated. We obtain a nonvanishing expectation value of the total spin of the residual ion-photoelectron system indicating significant relativistic interactions during the photoionization process.
authors.affiliation: Behlen Laboratory of Physics, University of Nebraska-Lincoln, 68588-0111, USA.
authors.forename: O
authors.initials: O
authors.lastname: Yenen
authors.forename: K W
authors.initials: KW
authors.lastname: McLaughlin
authors.forename: D H
authors.initials: DH
authors.lastname: Jaecks
authors.forename: M M
authors.initials: MM
authors.lastname: Sant'Anna
authors.forename: E A
authors.initials: EA
authors.lastname: Seddon