The multiparticle-multihole configuration mixing method and the RPA vacuum wave functionHYBRID

The multiparticle-multihole configuration mixing method (MPMH) method is a many-body approach that lies in between shell model and self-consistent mean-field methods. [1] Its core idea is the development of the nuclear wave function into mutliparticle-hole excitations of a reference state. Its first full implementation for even-even nuclei has already been achieved. [2] The aim of this project is to generalize it to odd nuclei and find new truncation schemes that will allow us to capture collectivity. For this second goal, we will analyse the vacuum wave function of RPA [3], which is a method widely used for describing collective excitations in nuclei. By calculating the components of the nuclear ground state that are found within this theory, we can select the particle-hole excitations that we will include in the MPMH wave function.

[1] Pillet, N., Berger, J. F., & Caurier, E. (2008). Variational multiparticle-multihole configuration mixing method applied to pairing correlations in nuclei. Physical Review C, 78(2), 024305.
[2] Robin, C., Pillet, N., Arteaga, D. P., & Berger, J. F. (2016). Description of nuclear systems with a self-consistent configuration-mixing approach: theory, algorithm, and application to the C 12 test nucleus. Physical Review C,93(2), 024302.
[3] Lenske, H., & Wambach, J. (1990). RPA ground state correlations in nuclei. Physics Letters B, 249(3-4), 377-380.