Updated Search for Electron Antineutrino Appearance at MiniBooNE

TL;DR

The MiniBooNE experiment's updated analysis with 52% more data shows a 91.1% confidence level favoring LSND-like neutrino oscillations over background, with an observed excess of electron-like events below 475 MeV.

Contribution

This study provides an updated search for electron antineutrino appearance with increased data, improving the statistical significance and consistency with previous LSND results.

Findings

Data favor LSND-like oscillations at 91.1% confidence level.

Observed excess of 38.6 ± 18.5 electron-like events below 475 MeV.

Improved compatibility with background-only hypothesis.

Abstract

The MiniBooNE experiment at Fermilab has updated its search for \nu_\mu-bar -> \nu_e-bar oscillations with data collected through May 2011. This represents a statistics increase of 52% over the result published in 2010. The data favor LSND-like oscillations over a background-only hypothesis at the 91.1% confidence level. While the new result remains equally consistent with LSND, the compatibility with the background-only hypothesis is improved. An excess of 38.6 +- 18.5 \nu_e-like events below 475 MeV is observed, consistent with the observation of such an excess in neutrino mode.