DECAY MODES OF HIGH-LYING SINGLE-PARTICLE STATES IN PB-209

The neutron decay of high-lying single-particle states in Pb-209 excit ed by means of the (alpha, He-3) 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 co nfirmed by the present data involving angular correlation measurements and the determination of branching ratios to low-lying levels in Pb-2 08. The structure located between 8.5 and 12 MeV excitation energy in Pb-209 displays large departures from a pure statistical decay with si gnificant direct feeding of the low-lying collective states (3-,5-) of Pb-208. At higher excitation energy up to 20 MeV, the measured neutro n decay is in agreement with the predictions of the statistical model.