The controversial $^{10}$He ground state resonance: A new observation using a 2p2n-removal from $^{14}$Be

A 2p2n-removal reaction from a $^{14}$Be beam was used to populate the two-neutron unbound $^{10}$He. A triple coincidence measurement of the $^{8}$He+n+n system, using the Modular Neutron Array (MoNA) and the Sweeper magnet, allowed for the ground state resonance of $^{10}$He to be reconstructed. Using a detailed Monte Carlo simulation, the resonance was fit with a Breit-Wigner lineshape having an energy of 1.60(25) MeV and width of 1.8(4) MeV. This result is in good agreement with previous measurements using 1-proton knockout reactions from $^{11}$Li, yet differs from experiments which used transfer reactions to populating $^{10}$He. The implications of this result, using the $^{14}$Be(-2p2n) reaction mechanism, with respect to the previous $^{10}$He measurements will be discussed.