Theoretical study on the dynamical correlation in Ar focusing on 3s excitation with outer-shell ionization due to electron impacts

We investigate the energy-loss spectra of high-energy electrons incident on Ar atoms using linear density response theory with a self-interaction correction. The energy region of the spectra covers from 24.5 to 30.0 eV, where many ns, np, and nd autoionizing resonant states from the 3s orbital of Ar exist with the continuum background from the 3p orbital. We compare the calculated spectra to recent energy-loss spectra measurements and identify the observed autoionizing resonant states. We also discuss the dependence of the spectra on the scattering angles and their physical meanings.