Symmetry conserving coupled cluster doubles wave function and the self-consistent odd particle number RPA

• Published in: The European physical journal. A, Hadrons and nuclei Vol. 56; no. 10
• Main Authors: Jemaï, M., Schuck, P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2020; Springer Nature B.V; EDP Sciences ; Springer [1998-....]
• Subjects: Clusters; Couplings; Equations of motion; Fermions; General Physics; Hadrons; Heavy Ions; Nuclear Fusion; Nuclear Physics; Nuclear Theory; Operators (mathematics); Particle and Nuclear Physics; Physics; Physics and Astronomy; Regular Article – Theoretical Physics; Symmetry; Wave functions
• ISSN: 1434-6001; 1434-601X
• DOI: 10.1140/epja/s10050-020-00276-9

Mixing single and triple fermions an exact annihilation operator of the Coupled Cluster Doubles wave function with good symmetry was found in Tohyama and Schuck (Phys Rev C 87:044316, 2013). Using these operators with the equation of motion method the so-called self-consistent odd particle number random phase approximation (odd-RPA) was set up. Together with the stationarity condition of the two body density matrix it is shown that the annihilation conditions allow to reduce the order of correlation functions contained in the matrix elements of the odd-RPA equations to a fully self consistent equation for the single particle occupation numbers. Excellent results for the latter and the ground state energies are obtained in an exactly solvable model from weak to strong couplings.