Electron-Electron Correlations and Dipole Selection Rules in Double Ionization of Helium by Proton Impact

Dipole selection rules and electron-electron correlation effects in double ionization of He by 6 MeV proton impact were studied by analyzing the correlation function differential in the polar emission angles of both electrons. In the data features are observed with a level of detail which is comparable to fully differential cross sections. Therefore, this method opens unexpected possibilities to study effects due to dipole selection rules and electron-electron correlations in unprecedented detail