The neutron decay of high-lying single-particle states in Pb209 excited by means of the (α,3He) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low lying levels in Pb208. The structure located between 8.5 and 12 MeV excitation energy in Pb209 displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states (3-,5-) of Pb208. At higher excitation energy up to 20 MeV, the measured neutron decay is in agreement with the predictions of the statistical model.
ASJC Scopus subject areas
- Nuclear and High Energy Physics