Unusual degree of angular anisotropy in the resonant Auger spectrum of Kr

The angular distribution parameter, {β}, has been measured for the resonant Auger spectra in Kr following 3d{→}5p excitation. Unusually low values, close to -1, were seen for two bands. From optical spectroscopy data these bands are assigned to the final states 4p⁴{(}³$P)5p${(}⁴P5/2, ⁴{P}3/2$, and $⁴D5/2). According to angular momentum transfer theory, some of the transitions could be parity unfavored, yielding {β} values of -1, but additional theory is required for a complete understanding. Implications for angular studies of highly resolved Auger spectra are discussed.