Dynamical Correlations in the Ground State: Transitions between One-Phonon Nuclear States

The probabilities of the E1 transition between the first 
 and @ excited levels in nuclei with pairing have been calculated within the self-consistent many-body nuclear theory and Green’s function method. Calculations for a long chain of even–even tin isotopes have been performed for the first time. The known Fayans energy density functional has been used to calculate the characteristics of phonons and E1 transitions between excited states. A good description has been achieved for existing experimental data for the reduced probabilities of E1 transitions between the first one-phonon states for the 116–124Sn isotopes but not for the 112Sn and 114Sn isotopes. Possible reasons for this discrepancy have been discussed; the most probable reason is the deformation in the ground or excited states. It has been shown that new dynamical three-quasiparticle correlations in the ground state should be taken into account to explain the experimental data for 116–124Sn.