Neutrinos in Large Extra Dimensions and Short-Baseline $\nu_e$ Appearance

TL;DR

This paper explores how sterile neutrinos in large extra dimensions with bulk masses can explain neutrino appearance anomalies and predicts testable effects in short-baseline experiments, while also implying neutrinos are Dirac particles.

Contribution

It introduces a novel LED model with bulk masses that suppress mixing of KK modes, providing a new mechanism to address neutrino anomalies and making specific experimental predictions.

Findings

Potential explanation for MiniBooNE and LSND anomalies

Enhanced sensitivity of Fermilab's Short-Baseline Neutrino Program to this scenario

Neutrinos are predicted to be Dirac particles, excluding neutrinoless double beta decay signals

Abstract

We show that, in the presence of bulk masses, sterile neutrinos propagating in large extra dimensions (LED) can induce electron-neutrino appearance effects. This is in contrast to what happens in the standard LED scenario and hence LED models with explicit bulk masses have the potential to address the MiniBooNE and LSND appearance results, as well as the reactor and Gallium anomalies. A special feature in our scenario is that the mixing of the first KK modes to active neutrinos can be suppressed, making the contribution of heavier sterile neutrinos to oscillations relatively more important. We study the implications of this neutrino mass generation mechanism for current and future neutrino oscillation experiments, and show that the Short-Baseline Neutrino Program at Fermilab will be able to efficiently probe such a scenario. In addition, this framework leads to massive Dirac neutrinos and thus precludes any signal in neutrinoless double beta decay experiments.