Indications of electron emission from the deuteron-deuteron threshold resonance

Electron emission in the deuteron-deuteron reaction supporting existence of the single-particle threshold resonance in 4He has been observed for the first time. The measured electron energy spectrum and the electron-proton branching ratio agree very well with the assumed electron-positron pair creation decay of the 0+ resonance state to the ground state and the detailed Monte Carlo simulations of the experimental energy spectrum.