# EPS-HEP2021 conference

26-30 July 2021
Zoom
Europe/Berlin timezone

## Explaining the MiniBooNE Excess Through a Mixed Model of Oscillation and Decay

Not scheduled
20m
Zoom

#### Zoom

Poster Neutrino Physics

### Speaker

Mr Stefano Vergani (University of Cambridge)

### Description

This talk presents a model of the electron-like excess observed by the MiniBooNE experiment comprising of oscillations involving two new mass states: $\nu_4$, at $\mathcal{O}(1)$ eV, that participates in oscillations, and $\mathcal{N}$, at $\mathcal{O}(100)$ MeV, that decays to $\nu+\gamma$ via a dipole interaction.
Short-baseline oscillation data sets, omitting MiniBooNE appearance data, are used to predict the oscillation parameters. We simulate the production of $\mathcal{N}$ along the Booster Neutrino Beamline via both Primakoff upscattering ($\nu A \to \mathcal{N} A$) and Dalitz-like neutral pion decays ($\pi^0 \to \mathcal{N} \nu \gamma$).
The simulated events are fit to the MiniBooNE neutrino energy and visible scattering angle data separately to find a joint allowed region at 95\% CL.
A point in this region with a coupling of $3.6 \times 10^{-7}$ GeV$^{-1}$, $\mathcal{N}$ mass of 394 MeV, oscillation mixing angle of $6\times 10^{-4}$ and mass splitting of $1.3$ eV$^2$ has $\Delta \chi^2/dof$ for the energy fit of 15.23/2 and 37.80/2. This model represents a significant improvement over the traditional single neutrino oscillation model.

Collaboration / Activity MiniBooNE Stefano Vergani sv408@cam.ac.uk

### Primary author

Mr Stefano Vergani (University of Cambridge)

### Co-authors

Mr Nicholas Kamp (Massachusetts Institute of Technology) Mr Alejandro Diaz (Massachusetts Institute of Technology) Prof. Carlos Argüelles (Harvard University) Prof. Janet Conrad (Massachusetts Institute of Technology) Prof. Mike Shaevitz (Columbia University) Dr Melissa Uchida (University of Cambridge)