Investigation of properties of 11− excited states of even-even nuclei

Background: The commissioning of new sources of monochromatic γ quanta will allow obtaining a large amount of new data on low-lying collective states of negative parity of even-even nuclei.Purpose: To derive relations between observables characterizing low-energy negative parity states in even-even nuclei and to investigate the dependence of $E2$ transitions between low-energy collective states in these nuclei on the parity of states.Methods: The Hamiltonian of the collective model and the fermionic Q-phonon representation of the vectors of collective states are used.Results: Relations between different $E1$ transition matrix elements are derived and the parity dependence of $E2$ transitions is investigated.Conclusion: Relations between the observables characterizing the low-lying collective states of both parities in even-even nuclei are obtained, which can be verified using experimental data produced by facilities generating intense monochromatic beams of γ quanta.