Constraints on electromagnetic properties of sterile neutrinos from MiniBooNE results

TL;DR

This paper constrains the electromagnetic dipole moments of sterile neutrinos using MiniBooNE data, showing these interactions can't fully explain the observed anomalies but can match some event distributions.

Contribution

It provides the first constraints on sterile neutrino electromagnetic moments over a broad mass range using MiniBooNE results, considering CP violation and both Dirac and Majorana cases.

Findings

Constraints on muon-to-sterile neutrino dipole moments established.

Electromagnetic interactions cannot fully explain MiniBooNE anomalies.

Some parameter values can reproduce the energy distribution of anomalous events.

Abstract

Among the class of models with small mixing angles between sterile and active neutrinos, we place constraints on the effective muon-to-sterile neutrino magnetic and electric dipole transition moments from the combined MiniBooNE results for the sterile neutrino mass range of $10\;\mathrm{MeV}<m_s<500\; \mathrm{MeV}$. Our results are valid for models with CP-violating interactions and for Dirac and Majorana sterile neutrinos. In addition, we show that such dipole electromagnetic interactions cannot be the main source of the anomalous events in the MiniBooNE experiment because they fail to reproduce the anomalous event distribution as a function of polar angle. However, good agreement with the anomalous event distribution in reconstructed energy can be achieved for some values of magnetic and electric moments.