With a relativistic partial-wave method we calculated numerically the pair-production polarization correlations between incident photon and emitted positron in the field of atoms with atomic number Z = 1, 50 and 92 for photons of energies k = 5 m(e)c(2) and 10 m(e)c(2). In this intermediate-photon-energy region, our partial-wave results show that the Born approximation works fine for low Z elements, as expected; while the high-energy approximation is poor for the prediction of the polarization correlations, just as its prediction for the unpolarized positron energy spectrum. This indicates that the energy is not yet high enough for the cases we considered. Our partial-wave results also show that the polarization correlations are almost independent of the atomic-electron screening.
關聯:
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
