EVOLUTION OF THE PYGMY DIPOLE RESONANCE IN Sn ISOTOPES

The(111-113,116-122,124)Sn isotopes were studied in light-particle-induced reactions to obtain the low-lying gamma-ray strength functions (GSFs) with the Oslo method. These data were further combined with the inelastic relativistic proton scattering GSFs to study the evolution of the pygmy dipole resonance (PDR) with an increasing neutron number. The PDR was found to be centered at approximate to 8 MeV in all isotopes. The fraction of the energy-weighted sum rule for dipole transitions exhausted by the PDR in these isotopes ranges from approximate to 1.5% to 3%, being the maximum for Sn-120.

Automated summary

The low-lying gamma-ray strength functions (GSFs) of Sn isotopes were studied using the Oslo method and combined with the inelastic relativistic proton scattering GSFs. The evolution of the pygmy dipole resonance (PDR) with increasing neutron number was investigated. The PDR was found to be centered at approximately 8 MeV in all isotopes, with the largest contribution occurring in Sn-120.