Séminaire de Ruben de Groote: Studying radioactive nuclei and molecules with laser spectroscopy techniques

Studying radioactive nuclei and molecules with laser spectroscopy techniques

Ruben de Groote, Institute for nuclear and radiation physics, KU Leuven (Université de Louvain), Belgique

One of the central themes in nuclear structure research revolves around bridging the gap between QCD, the fundamental theory for quarks and gluons, and the intricate structure of real nuclei with many protons and neutrons. Measurements of atomic structure of radioactive isotopes provides invaluable information here, since it provides model-independent values for magnetic dipole moments, electrical quadrupole moments and changes in the nuclear size. Much of the recent developments have thus been devoted to improving the efficiency of such techniques, so that increasingly short-lived and/or hard-to-produce nuclei can be studied. After giving a flavour of the instrumentation and techniques which we use, I will discuss recent results obtained on various isotopic chains, which will illustrate how the dialogue between theory and experiment leads us to new insights.

Given the impressive progress in atomic, molecular and optical sciences it is worthwhile to evaluate new directions the field can take to go beyond the current state-of-the-art. This may bring higher-order effects (e.g. hyperfine anomalies, magnetic octupole moments, information beyond the mean-squared charge radius…) into reach even for radioactive nuclei. Conversely, the impressive instrumentation that was developed to efficiently produce, extract and study short-lived radioactive atoms or molecules may be of interest for other fields. As an example, I will conclude my talk by showing the first optical spectroscopy of radioactive radium-fluoride molecules, a study which was motivated by searches for physics beyond the standard model.