Research Group Alexandre Obertelli
Exotic Nuclear Matter

Neutron-rich nuclei

Atomic nuclei are mainly governed by the strong force and quantum mechanical laws. In low-energy effective theories, they are commonly described as systems of nucleons interacting through the nuclear forces. In a shell model picture, the nuclear shell gaps represent the backbone of nuclear structure and are a direct fingerprint of the nuclear interactions. Magic numbers of nucleons are well established for stable nuclei: 2, 8, 20, 28, 50, 82, 126 but are known not to be universal over the nuclear chart. Indeed, the nuclear shell structure is known to change, sometimes drastically, with the number of protons and neutrons, revealing how delicate the arrangement of interacting nucleons is.

Strong shell reordering may occur in several new regions of the nuclear chart at reach with current setups and beam intensities.

To achieve sufficient statistics and resolution for the spectroscopy of these rare isotopes produced at very low yields, we focus on in-beam gamma spectroscopy with the combination of gamma detectors, a liquid hydrogen target and a vertex tracker device dedicated to quasi free scattering reactions to populate the nuclear states of interest [1,2].

We perform our experiment to reveal the structure of neutron-rich nuclei at the frontier of what can be accessed experimentally. We focus our experiments at the best Radioactive Isotope Beam facility world-wide, the RIBF of RIKEN, Japan.

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