Search for the Lambda-nn state using electron scattering

A bound state of two neutrons and a Lambda has been indicated to exist by a heavy ion beam experiment at GSI. However, the baryon interactions which have been investigated through scattering experiments and (hyper)nuclear spectroscopy cannot explain any bound states in the three-body isotriplet system with a Lambda. On the other hand, the Lambda-nn is predicted to exist as a resonant state in some theoretical calculations. A missing mass experiment using electron scattering has sensitivity to measure either state (bound or resonant states). In contrast to conventional reaction spectroscopy with hadron beams, more accurate and precise measurements on Lambda binding energies which are required to pin down the existence of Lambda-nn have been realized by recent reaction spectroscopy with the (e,e’K⁺) reaction at Jefferson Lab, U.S. Moreover, the measured energy and width would provide us interaction information between a Lambda and neutron for which no scattering data exist. The Lambda-nn search experiment will be carried out with a tritium target via the (e,e’K⁺) reaction at JLab Hall A on October—November, 2018. I will present an overview and status of the experiment.