Microscopic models of nuclear collective vibrations

Collective vibrations represent fundamental excitation modes in atomic nuclei. High-frequency collective vibrations of different types and multipolarities – giant resonances are observed across the nuclear chart [1]. An interesting example is the Pygmy dipole mode, whose ongoing experimental studies [2] also stimulate theoretical investigations and model improvements.

A well-established many-body method used to describe nuclear collective vibrations, starting from nucleonic degrees of freedom, is the Random-phase approximation (RPA) [1]. Despite the success of the RPA in the description of the gross features of giant resonances, a detailed understanding of nuclear collective motion requires more sophisticated methods. To overcome the limitations of the RPA, several methods were proposed for even [3-6] and odd nuclei [7,8] in recent years.

The candidate will investigate novel quantum many-body methods that go beyond the RPA. An essential part of the research includes the development of numerical codes. Developed formalism will be applied to the study of collective and non-collective modes in medium-heavy spherical nuclei, with an emphasis on electromagnetic and charge-exchange processes.

References

[1] Harakeh, Woude, Giant resonances, Calderon press Oxford 2001
[2] Spieker et al, Phys. Rev. Lett 125, 102503 (2020)
[3] Gambacurta, Phys. Rev. Lett 125, 212501 (2020)
[4] Knapp et al, Phys. Rev C 92, 054315 (2015)
[5] Litvinova et al, Phys. Rev. Lett. 105, 022502 (2010)
[6] Papakonstantinou, Phys. Rev. C 90, 024305 (2014)
[7] Shen et al, Phys. Rev. C 101, 044316 (2020)
[8] De Gregorio et al, Phys. Rev. C 99, 014316 (2019)