Precision measurements of electromagnetic matrix elements as a test of Ab-Initio calculations in light nuclei

Recent ab-initio shell model calculations of light nuclei have underlined the importance of 3-body forces. Gamma-ray spectroscopy of certain excited states in light nuclei can test new formulations of the interaction, as both the diagonal and off diagonal matrix elements are sensitive to it. A particularly interesting set of cases lie in the A = 10 systems, $^{10}$Be, $^{10}$B, and $^{10}$C, where the inclusion of 3-body forces is found to invert the sequence of states. This has been attributed to the important contribution of the 3-body interactions to the overall spin-orbit force. Precise ($<$10{\%}) matrix elements are needed to challenge the latest calculations, requiring a new generation of improved experiments. Lifetimes of excited levels in A = 10 nuclei, populated in the $^{6}$Li($^{6}$Li, xpxn) reaction, will be determined using high velocity DSAM lineshape measurements. Preliminary results of the experiment will be presented and discussed in terms of recent ab-initio shell model calculations. This research was supported by the DOE Office of Nuclear Physics under contract DE-AC02-06CH11357.