Superallowed alpha decay to doubly magic 100Sn

Dariusz Seweryniak, Argonne National Laboratory
Wednesday, Feb 13, 4:10 PM - Nuclear Science Seminar
1200 FRIB Laboratory

Abstract:  Alpha decay has been a probe of nuclear structure and clustering in nuclei since the dawn of nuclear physics. However, microscopic description of [alpha]-decay rates remains to be a challenge. The island of [alpha] emitters near the N=Z line, 'north-east' of 100Sn, provides valuable data on the role of proton-neutron correlations in the [alpha]-particle formation. In fact, superallowed [alpha] decay has been proposed to occur in this region due to enhanced interactions between neutrons and protons, which occupy the same orbitals. During the talk, the recent observation of the superallowed [alpha]-decay chain 108Xe-104Te to doubly magic 100Sn, using the recoil-decay correlation technique with the Argonne Fragment Mass Analyzer at ATLAS, will be presented. This is an important stepping-stone towards developing a microscopic model of [alpha] decay since it is only the second case of [alpha] decay to a doubly magic nucleus, besides the benchmark 212Po [alpha] decay to 208Pb. The decay properties of 108Xe and 104Te indicate that the reduced [alpha]-decay width in at least one of these nuclei is a factor of 5 larger than in 212Po, which confirms their superallowed character. More precise measurements of [alpha]-decay properties along the 108Xe-104Te chain and of the neighboring nuclei would be invaluable for quantitative comparisons with existing [alpha]-decay models.