Monday, October 7, 2013

Transfer Reactions: Probing Nuclear Structure Relevant to Astrophysics

Brett Manning (Rutgers University)

Nuclei with a few nucleons beyond shell closures are important in understanding the evolution of single-particle structure, which is critical to the benchmarking of nuclear models. With radioactive ion beams, studies near the double shell closure 132Sn have been made possible. While the single-neutron states in 133Sn and 131Sn have recently been verified to be highly pure [1,2], it is important to study further from the N=82 closed shell. The (d,p) reaction was measured with the radioactive ion beams of 126Sn and 128Sn in inverse kinematics at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory, utilizing the SuperORRUBA silicon detector array [3]. Angular distributions of reaction protons were measured for several states in 127Sn and 129Sn in order to determine angular momentum transfers, differential cross-sections, and extract spectroscopic factors. Such information is critical for calculating direct (n,γ) cross sections for the r-process and for constraining shell model parameters in the A∼130 region. Combined with previous experiments on 130Sn and 132Sn, these results provide a complete set of (d,p) reaction data on even tin isotopes between doubly-magic 132Sn and stable 124Sn. This work is supported in part by the U.S. Department of Energy and National Science Foundation.

[1] K.L. Jones, et al., Nature 465, 454 (2010) and Phys. Rev. C 84, 034601 (2011).

[2] R.L. Kozub et al., Phys. Rev. Lett. 109, 172501 (2012).

[3] D.W. Bardayan et al., NIMA 711, 160 (2013).