Four Decades of Hyperfine Anomalies

Abstract

Abstract Isotopic differences in the distribution of nuclear charge and magnetization give rise to “hyperfine structure anomalies” which were observed already in the 1950s. More recently, the distribution of nuclear magnetization has been found to complicate the interpretation of the measured hyperfine splittings in highly charged hydrogen-like ions. In this paper, results of numerical calculations for a few hydrogen-like systems ( 133 Cs, 165 Ho, 185,187 Re and 209 Bi) of current experimental interest are presented in terms of moments of the nuclear charge and magnetization distribution, thereby displaying directly the sensitivity and emphasizing the need for a better understanding of nuclear wavefunctions. In addition, we also present results of many-body perturbation theory calculations for Cs hyperfine anomalies, in connection with experiments planned at ISOLDE.