Effect of core vibration on the neutron-hole states ofPb207

Abstract

Three neutron-hole states---$1{i}_{\frac{13}{2}}$, $2{f}_{\frac{7}{2}}$, and $1{h}_{\frac{9}{2}}$---in $^{207}\mathrm{Pb}$ are found to be affected strongly due to the coupling of these states with the ${3}^{\ensuremath{-}}$, ${5}^{\ensuremath{-}}$, ${2}^{+}$, ${4}^{+}$, and ${6}^{+}$ vibration states of $^{208}\mathrm{Pb}$. The unperturbed shell model energies of these states are found at 2.00, 3.00, and 3.90 MeV, respectively. The fragmentations of $1{i}_{\frac{13}{2}}$, $1{h}_{\frac{9}{2}}$, and $1{h}_{\frac{11}{2}}$ states, as observed in a recent $^{208}\mathrm{Pb}$ ($^{3}\mathrm{He}$,$\ensuremath{\alpha}$) reaction, can be quantitatively accounted for in terms of these altered level positions together with the hole-core coupling scheme.NUCLEAR STRUCTURE Deduced shell model energies of $^{207}\mathrm{Pb}$.