# Mono-energetic anti neutrino spectrum

Are there any nuclear decays that produce a mono-energetic anti-neutrino spectrum? I suspect that there aren't any but I can't justify why.

• Two-body beta decays would have a monoenergetic antineutrino spectrum, but the examples given in the answers to that question would have a large continuous-energy antineutrino background from the more common three-body decay. – rob Apr 26 '18 at 19:32