Stability of the Neutrino

Limits of > ${10}^5$ astronomical units are set on the decay length of an electron antineutrino ${\overline{\nu }}_e$ via the process ${\overline{\nu }}_e\to {\nu }^{\prime }+\gamma$ for $E_{\gamma }$ in the range 0.1-0.5 MeV using the results from a well-shielded detector in the vicinity of a fission reactor. This mode of decay is therefore ruled out as a possible explanation for the paucity of solar neutrinos revealed by the experiment of Davis.