Observation of the Helium 7 Lambda hypernucleus by the (e,e'K+) reaction
  An experiment with a newly developed high-resolution kaon spectrometer (HKS) and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab (JLab). The ground state of a neutron-rich hypernucleus, He 7 Lambda, was observed for the first time with the (e,e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The he 7 Lambda binding energy supplies the last missing information of the A=7, T=1 hypernuclear iso-triplet, providing a new input for the charge symmetry breaking (CSB) effect of \Lambda N potential. 
S. N. Nakamura, A. Matsumura, Y. Okayasu, T. Seva, V. M. Rodriguez, P.   Baturin, L. Yuan, A. Acha, A. Ahmidouch, D. Androic...
nucl-ex