The MiniBooNE anomaly and heavy neutrino decay

Understand

The anomaly in the low energy distribution of quasi-elastic neutrino events reported by the MiniBooNE collaboration is discussed.

• We show that the observed excess of electron-like events could originate from the production and decay of a heavy neutrino ($\nu_h$) in the MiniBooNE detector.
• The $\nu_h$ is created by mixing in $\nu_\mu$ neutral-current interactions and decays radiatively into $ \nu \gamma$ due to a transition magnetic moment between the $\nu_h$ and a light neutrino $\nu$.
• The energy measured in the detector arises from the subsequent conversion of the decay photon into a $\pair$ pair within the detector volume.