The MiniBooNE experiment reported results from the analysis of $\nu_e$ and $\overline{\nu}_e$ appearance searches, which showed an excess of signal-like events at low reconstructed neutrino energies with respect to the expected background. A proposed explanation for this anomaly assumes the existence of a heavy ($\sim 50$~MeV) sterile neutrino. These $\nu_h$ would be produced by $\nu_\mu$ electromagnetic interactions with the target, through a transition magnetic dipole moment, and by neutral current interactions, due to the $\nu_\mu - \nu_h$ mixing. A fraction of them decays radiatively inside the detector. The emitted photons are misidentified as electrons or positrons in MiniBooNE, contributing therefore to the signal.

We have studied the $\nu_h$ production by coherent and incoherent electroweak interactions on CH$_2$ and Ar targets, present in the MiniBooNE and the Short Baseline Neutrino (SBN) detectors at Fermilab. Following the $\nu_h$ propagation and subsequent decay inside the detector, we are able to obtain the energy and angular distributions of the final photons. Within the allowed range of model parameters, we have obtained the best fit to describe the MiniBooNE excess of events. To further investigate this scenario, we have calculated the expected signal at the SBN detectors. The distinctive shape and total number of photon events from this mechanism makes its experimental investigation feasible.