Nuclear properties in the lead region within the quasiparticle-phonon nuclear model

Abstract

The properties of the low-lying states and giant resonances in 208Pb are calculated within the quasiparticle-phonon nuclear model, the model parameters being fixed. The fragmentation of the deep hole states 1 h 11 2 , 1 g 7 2 and 1 g 9 2 in 207Pb and 1 g 7 2 , 1 g 9 2 , 2 p 1 2 and 2 p 3 2 in 203, 205, 207Tl is calculated, and qualitative agreement with the available experimental data is obtained. The s-, p- and d-wave neutron strength functions are calculated for 206Pb + n and 207Pb + n resonances. Their energy dependence is correctly described up to 0.9 MeV above the neutron binding energy B n. The reduced E1 transition probabilities and the total photoabsorption cross sections σ γt in 206, 208Pb are calculated. It is shown that substructures observed in the energy dependence σ γt are caused by the fragmentation of one-phonon states. A fine structure of the isoscalar quadrupole resonance is explained, and the description of the LEOR and HEOR in 208Pb is obtained, which is in agreement with the experimental data.