Author:

Keywords:

Science & Technology, Physical Sciences, Physics, Nuclear, Physics, Particles & Fields, Physics, ab initio many-body methods, symmetry breaking and restoration, near-degenerate finite quantum systems, PAIRING FORCE MODEL, PLESSET PERTURBATION-THEORY, PROJECTED STATES, QUANTUM-CHEMISTRY, CONVERGENCE, SYSTEMS, nucl-th, quant-ph, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 5106 Nuclear and plasma physics, 5107 Particle and high energy physics

Abstract:

© 2016 IOP Publishing Ltd. We have recently extended many-body perturbation theory (MBPT) and coupled-cluster theory performed on top of a Slater determinant breaking rotational symmetry to allow for the restoration of the angular momentum at any truncation order (Duguet 2015 J. Phys. G: Nucl. Part. Phys. 42 025107). Following a similar route, we presently extend Bogoliubov MBPT and Bogoliubov coupled cluster theory performed on top of a Bogoliubov reference state breaking global gauge symmetry to allow for the restoration of the particle number at any truncation order. Eventually, formalisms can be merged to handle SU(2) and U(1) symmetries at the same time. The long-term goal relates to the ab initio description of near-degenerate finite quantum systems with an open-shell character.