Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Short Baseline Neutrino Oscillations and a New Light Gauge Boson

Ann E. Nelson, Jonathan Walsh

TL;DR

The paper introduces a renormalizable extension of the Standard Model with three sterile neutrinos and a light $U(1)_{\mathrm{B-L}}$ gauge boson (paraphoton) to generate a flavor-universal, MSW-like matter potential that alters short-baseline neutrino oscillations. By constructing a six-neutrino mass matrix and analyzing the effective Hamiltonian in a specially chosen basis, the authors show that active-sterile mixing can be energy-dependent and enhanced for anti-neutrinos, potentially aligning the LSND signal with MiniBooNE's null results at higher energies. A thorough numerical scan demonstrates viable regions of parameter space that fit LSND and MiniBooNE while satisfying CHOOZ and other constraints; the model also offers partial explanations for MiniBooNE's low-energy electron-like excess and makes a robust prediction that MiniBooNE anti-neutrino oscillations should be observable and larger than the neutrino oscillations in the same energy range. The analysis accommodates astrophysical and cosmological considerations via a chameleon mechanism that raises the paraphoton mass in dense environments, thereby mitigating stellar and supernova energy-loss constraints when choosing appropriate parameters.

Abstract

We consider a model of neutrino oscillations with three additional sterile neutrinos and a gauged B-L interaction. We find allowed values of the model parameters which can reconcile the results of the evidence for antimuon neutrino to antielectron neutrino conversion seen at the LSND neutrino oscillation experiment with the null results of the MiniBooNE experiment. A portion of the low energy excess of electron neutrino events seen at MiniBooNE can arise naturally, and we make a quantitative prediction for the forthcoming anti-neutrino oscillation results at MiniBooNE.

Short Baseline Neutrino Oscillations and a New Light Gauge Boson

TL;DR

The paper introduces a renormalizable extension of the Standard Model with three sterile neutrinos and a light gauge boson (paraphoton) to generate a flavor-universal, MSW-like matter potential that alters short-baseline neutrino oscillations. By constructing a six-neutrino mass matrix and analyzing the effective Hamiltonian in a specially chosen basis, the authors show that active-sterile mixing can be energy-dependent and enhanced for anti-neutrinos, potentially aligning the LSND signal with MiniBooNE's null results at higher energies. A thorough numerical scan demonstrates viable regions of parameter space that fit LSND and MiniBooNE while satisfying CHOOZ and other constraints; the model also offers partial explanations for MiniBooNE's low-energy electron-like excess and makes a robust prediction that MiniBooNE anti-neutrino oscillations should be observable and larger than the neutrino oscillations in the same energy range. The analysis accommodates astrophysical and cosmological considerations via a chameleon mechanism that raises the paraphoton mass in dense environments, thereby mitigating stellar and supernova energy-loss constraints when choosing appropriate parameters.

Abstract

We consider a model of neutrino oscillations with three additional sterile neutrinos and a gauged B-L interaction. We find allowed values of the model parameters which can reconcile the results of the evidence for antimuon neutrino to antielectron neutrino conversion seen at the LSND neutrino oscillation experiment with the null results of the MiniBooNE experiment. A portion of the low energy excess of electron neutrino events seen at MiniBooNE can arise naturally, and we make a quantitative prediction for the forthcoming anti-neutrino oscillation results at MiniBooNE.

Paper Structure

This paper contains 12 sections, 50 equations, 4 figures.

Table of Contents

  1. Introduction
  2. The LSND and MiniBooNE Experiments
  3. A Renormalizable Model of Neutrino Masses with a Light $B-L$ Gauge Boson
  4. Oscillation Probabilities
  5. Constraints on Parameters from Neutrino Oscillation Experiment
  6. Astrophysics
  7. Chameleon effect in stars
  8. Numerical estimate of chameleonic paraphoton effect on stellar energy loss
  9. Supernova 1987A
  10. Nucleosynthesis constraints
  11. Numerical Analysis
  12. Summary

Figures (4)

  • Figure 1: A histogram of the MiniBooNE oscillation probability for neutrinos in the energy region from 200 to 475 MeV
  • Figure 2: The average MiniBooNE neutrino oscillation probability in the energy region from 200- 475 MeV vs. the region above 475 MeV
  • Figure 3: The MiniBooNE anti-neutrino oscillation probability in the region from 200 to 475 MeV vs. the region above 475 MeV
  • Figure 4: The cumulative distribution for ratios of anti-neutrino to neutrino oscillation probability, below (black, upper curve) and above (blue or gray, lower curve) 475 MeV energy. For a fixed oscillation probability ratio R, the vertical axis is the fraction of fit points with ratio greater than R