Neutron-removal reactions in the 100Sn region

Characterizing the nature of single-particle states outside of double shell closures is essential to a fundamental understanding of nuclear structure. This is especially true for those doubly magic nuclei that lie far from stability and where the shell closures influence nucleosynthetic pathways. The region around 100Sn is important due to the proximity of the N=Z=50 magic numbers, the proton drip line, and the end of the rp-process. However, owing to low production rates, there is a lack of spectroscopic information and no firm spin-parity assignment for ground states of odd-A isotopes close to 100Sn. Neutron knockout reaction experiments on a beam of 108Sn have been performed at the NSCL. By measuring gamma rays and momentum distributions of the reaction residues, the spins of the ground and first excited states of 107Sn have been established. The results are compared to eikonal-model reaction calculations. One-neutron knockout reactions from below the N=50 closed shell have been observed and estimated with the measurement of inclusive and exclusive cross sections.