Strong dynamical effects in the Kβ2 and Lγ2,3 X-ray emission spectra of lanthanum

Abstract

The Kβ1,3 (K å M3,2), Kβ2I,II (K å N3,2), and the Lγ2,3 (L1 å N2,3) X-ray emission spectra from lanthanum have been measured, using high resolution crystal spectrometers. For the first time we observe an undisturbed 4p32 hole state together with a 4p12 hole state that is spread over an extended energy range. In comparison with theoretical calculations we show that in this case the quasi-particle picture only breaks down for the 4p12 core hole, due to very strong dynamical dipolar fluctuation and associated decay processes of the 4p12 core hole.