Distribution of the high-spin 2f7/2, 1h9/2and 1i13/2proton states in145Eu and the effect of high-lying vibrational states of208Pb on the deep neutron 1g7/2and 1g9/2states of207Pb

Abstract

The shell-model strength distributions of the high-spin 2f7/2, 1h9/2 and 1i13/2 proton states in 145Eu and 1g7/2 and 1g9/2 deep neutron hole states in 207Pb have been quantitatively explained within the framework of the particle (hole) vibrational scheme. In 145Eu proton states are coupled with the collective states arising from the quadrupole and octupole phonon states of 144Sm to explain the fragmentation of the high-spin proton states as detected in the 144Sm( alpha , t) reaction. Good agreement has been obtained with the four discrete 2f7/2 states and one discrete 1h9/2 state within the 5 MeV excitation energy in 145Eu. The wavefunctions obtained from the diagonalisation of the Hamiltonian matrices have been utilised to calculate B(E2) and B(M1) transition rates as well as the electric quadrupole and magnetic dipole moments of the different 7/2-, 9/2- and 13/2+ states of 145Eu. In 207Pb the neutron hole states are mixed with both the low-lying and high-lying vibrational states arising from the giant resonances in 208Pb to obtain the full spectrum of the 1g7/2 and 1g9/2 neutron hole states. The experimental result from the 208Pb(3He, alpha ) reaction provides convincing support for the calculation from the hole-core coupling model.