Direct Reactions with Exotic Beams (DREB2016)

Structure of $^{110}$Zr - first spectroscopy and its implications for shell evolution and the r-process

11 Jul 2016, 15:55

15m

Scotiabank Theatre (St. Mary's University)

Contributed Oral/Poster Shell evolution through direct reactions - Spectroscopy of nuclear levels and nuclear shapes through direct reactions

Speaker

Nancy Paul (CEA Saclay)

Description

A predicted Z=40 subshell closure in $^{110}$Zr has long been considered a potential explanation for the excess of elemental abundances before the A=130 r-process peak. We performed the first spectroscopy of this nucleus at the RIKEN-RIBF facility, populating the low-lying levels via (p,2p) knockout and measuring the energies with the MINOS tracker and DALI2 NaI array. We will present first spectroscopy results, $^{111}$Nb(p,2p)$^{110}$Zr and $^{112}$Mo(p,3p)$^{110}$Zr cross sections, complementary analysis of neighboring nuclei, implications for structural evolution in the 50$<$N$<$82 region, and the impact on our understanding of the formation of the A=130 r-process peak. Additionally, we report on a broader, ongoing study of (p,2p) and (p,3p) quasi-free scattering cross sections as measured during the SEASTAR (Shell Evolution And Search for Two-plus energies At RIBF) campaigns.