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Diabatic and Adiabatic Collective Motion in a Model Pairing System

Takashi Nakatsukasa·Niels R. Walet
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Abstract

Large amplitude collective motion is investigated for a model pairing Hamiltonian containing an avoided level crossing. A classical theory of collective motion for the adiabatic limit is applied utilising either a time-dependent mean-field theory or a direct parametrisation of the time-dependent Schrödinger equation. A modified local harmonic equation is formulated to take account of the Nambu-Goldstone mode. It turns out that in some cases the system selects a diabatic path. Requantizing the collective Hamiltonian, a reasonable agreement with an exact calculation for the low-lying levels are obtained for both weak and strong pairing force. This improves on results of the conventional Born-Oppenheimer approximation.

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BibTeXRIS

Takashi Nakatsukasa, Niels R. Walet. 1997-10-16. Diabatic and Adiabatic Collective Motion in a Model Pairing System. https://doi.org/10.1103/physrevc.57.1192

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