Probing the Single-Particle Neutron Origin of the Pygmy Dipole Resonance

Abstract

The first comprehensive study of the single-particle structure of pygmy dipole resonance (PDR) in double-magic Pb and semi-magic Sn nuclei with an excess of neutrons is presented. Theoretical calculations are carried out with a microscopic approach based on the energy-density functional plus quasiparticle-phonon model (EDF + QPM) and combined with nuclear reaction theory. The obtained theoretical results are compared to novel Pb(d,p)Pb and Sn(d,pγ)Sn experiments and other available experimental data. In addition, various properties of the dipole strength distributions are discussed in order to elucidate the microscopic structure of the PDR in detail. The studies will support ELI-Gamma-Above-Neutron-Threshold (ELIGANT) day-one experiments at the ELI-NP.