Speaker
Description
The region around the doubly magic nucleus 100Sn provides a unique testing ground for nuclear structure models at the proton drip line and near the (N=Z) line. Recent experiments performed at the Radioactive Isotope Beam Factory (RIBF), Japan, using the DALI2+ gamma-ray spectrometer have enabled new spectroscopic studies in this key region.
In this contribution, I will report on the first in-beam gamma-ray spectroscopy of 100Sn. Excited states were populated via proton-induced neutron-knockout reactions from neutron-deficient 101,102Sn isotopes, providing the first direct information on the excitation spectrum of this doubly magic nucleus. The results offer new insights into the robustness of the (Z=N=50) shell closures and the nature of proton and neutron excitations across the shell gaps.
In addition, recent Coulomb-excitation measurements of 98Pd, 100Cd, and 102Sn along N=52 will be presented. The extracted transition strengths, together with large-scale shell-model calculations, provide stringent constraints on the effective proton and neutron charges in the vicinity of 100Sn. The results indicate enhanced neutron polarization effects and contribute to a consistent description of quadrupole collectivity in this region.
The experimental findings will be discussed in the broader context of shell evolution, effective charges, and the doubly magic character of 100Sn.