High-amplitude vibrational states of atomic nuclei

The development of the earlier formulated theory of high-amplitude vibrational states of nuclei is advanced. The case is considered when oscillation amplitude of the self-consistent field is large and the collective frequency is small in comparison with the single-particle one. There are no single-particle states under the circumstances, hence the routine Hartree-Fock method is invalid. The correlation energy must be taken into account in the equations of motion. The discussion is conducted on the example of arbitrary number of interacting phonons. The consideration allows naturally classify collective states over interaction strength and introduce the external field in the theory in such a way, so both 'strong' and 'weak' phonons correspond resonance frequencies. For the practically important case of external fields acting a finite time an expression is obtained for average excitation energy of the system