Photon momentum transfer in one-photon single ionization of helium : The influence of electron correlation
The photon momentum transfer in the one-photon single ionization (1PSI) of helium is theoretically and experimentally studied. The influence of electron correlations is found to be displayed in the dimensionless photon momentum-transfer factor F, which takes a value of 8/5 for the 1PSI of the 1s state of hydrogen. For the ground state of helium, we find that F first decreases and then increases wi