Fragmentation of Single-Particle Strength around the Doubly Magic Nucleus Sn 132 and the Position of the 0f5/2 Proton-Hole State in In 131

Abstract

Spectroscopic factors of neutron-hole and proton-hole states in Sn131 and In131, respectively, were measured using one-nucleon removal reactions from doubly magic Sn132 at relativistic energies. For In131, a 2910(50)-keV γ ray was observed for the first time and tentatively assigned to a decay from a 5/2-state at 3275(50) keV to the known 1/2-level at 365 keV. The spectroscopic factors determined for this new excited state and three other single-hole states provide first evidence for a strong fragmentation of single-hole strength in Sn131 and In131. The experimental results are compared to theoretical calculations based on the relativistic particle-vibration coupling model and to experimental information for single-hole states in the stable doubly magic nucleus Pb208.