Angular distribution of photoelectrons of Xe5pspin-orbit components between 20 and 105 eV

With the use of synchrotron radiation, the β parameters of the Xe $5p$ components have been measured between 20 and 105 eV in a regime in which both relativistic and many-body effects are important. The experimental β values of ²P3/2 and ²P1/2 are found to be in good accord with the relativistic random-phase-approximation (RRPA) theory, but only in fair agreement with the Dirac-Fock prediction. Similarly, the branching ratio σ(²P3/2)σ(²P1/2) agrees well with the RRPA. However, the Dirac-Fock model accounts satisfactorily for the difference in the β values of the components indicating similar many-body effects acting on both components. A brief description is given of the new gas-phase angle-resolved electron-spectrometry system used in this work.