Eduardo Saúl Sala

Production and radiative decay of heavy neutrinos at the Booster Neutrino Beam

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 is based on the existence of a heavy ($sim 50$~MeV) sterile neutrino. These $nu_h$ would be produced by $nu_mu$ electromagnetic interactions, through a transition magnetic dipole moment, and by neutral current interactions on nuclei. A fraction of them decays radiatively inside the detector. The emitted photons are misidentified as electrons or positrons in MiniBooNE. We have investigated 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 (MicroBooNE, SBND and ICARUS) at Fermilab. Following the $nu_h$ propagation inside the detector we are able to obtain the energy and angular distributions of the final photons. Within the valid range of model parameters, we have obtained the best-fit parameters to describe the MiniBooNE excess of events. To further investigate this scenario, we have obtained the expected the signal at the SBN detectors. The distinctive shape and total number of photon events from this mechanism makes its experimental investigation feasible.