Experimental study of atomic 4<i>d</i>giant resonances by photoabsorption and photoelectron spectroscopy: Sm, Eu, and Gd

Abstract

Excitation and decay of the 4${d}^{\mathrm{\ensuremath{-}}1}$(4,\ensuremath{\epsilon})f giant resonances of atomic Sm, Eu, and Gd have been investigated by photoabsorption and photoelectron spectroscopy. The experimental total and partial cross sections are compared to those predicted by many-electron theories. Autoionization into the 4${f}^{\mathrm{\ensuremath{-}}1}$\ensuremath{\epsilon}l continuum dominates. The character of the giant resonances is closer to that of a 4${d}^{\mathrm{\ensuremath{-}}1}$4f resonance than to that of a 4${d}^{\mathrm{\ensuremath{-}}1}$\ensuremath{\epsilon}f shape resonance encountered for Ba and La.