Dipole Response of Medium-Mass Nuclei

• Applicant: Professor Dr. Andreas Zilges
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460150577

The electromagnetic interaction between photons in the MeV energy range and atomic nuclei is governed by the nuclear dipole response, which has been shown to be important for understanding nucleosynthesis in the universe, which is related to the symmetry parameter in the equation of state of nuclear matter, and which may be correlated with the neutron skin of nuclei. Due to the increasing asymmetry between neutrons and protons, further enhancement of the electric dipole strength at low energies is expected in exotic neutron-rich nuclei. Despite the enormous general progress in models of nuclear structure, a robust prediction of the properties of the dipole strength is still a challenge. The goal of this project is to measure various observables of the dipole response in medium-mass nuclei around the Z=28 and N=28 shell closures with complementary experimental probes. Such nuclei are an ideal testing ground because the level density up to the particle threshold is low enough for a detailed analysis. On the other hand, theoretical calculations in these nuclei are very well developed and it will be important to see how reliably they can predict the properties of the excitations. For this purpose we plan a combination of experiments with photon, proton and alpha beams at different experimental facilities and compare the results with state-of-the-art theoretical calculations. These measurements will fill the gaps in the knowledge, provide additional points in the mid-mass systematics, and give much needed feedback to the theoreticians.

• DFG Programme: Research Grants