Particle decay of the isoscalar giant dipole resonance in 208Pb

Abstract

The direct particle decay of the isoscalar giant dipole resonance (ISGDR) has been studied in 208Pb using the (α, α′ p) and (α, α′ n) reactions at a bombarding energy of 200 MeV. The direct-decay channels of proton and neutron emissions were observed in coincidence with the scattered α-particles in order to study the population of proton-hole states in 207T1 and neutron-hole states in 207Pb. The results of the partial and total branching ratios allowed us to test recently performed continuum-RPA (CRPA) calculations for the ISGDR and thereby to learn about its microscopic structure.