Results from the LSND Neutrino Oscillation Search

TL;DR

The LSND experiment searched for neutrino oscillations by detecting electron antineutrino appearance and set bounds on oscillation parameters, finding no significant excess over background.

Contribution

This paper reports the first bounds on neutrino oscillation parameters from the LSND experiment using a novel detection method.

Findings

Observed 5 candidate events with an expected background of 6.2 events.

Set upper limits on neutrino oscillation parameters: Delta m^2 < 0.07 eV^2 and sin^2(2θ) < 6×10^{-3}.

Provided constraints on neutrino oscillation models.

Abstract

The Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos Meson Physics Facility sets bounds on neutrino oscillations in the appearance channel nu_mu_bar --> nu_e_bar by searching for the signature of the reaction nu_e_bar p --> e^+ n: an e$^+$ followed by a 2.2MeV gamma ray from neutron capture. Five e^{+/-} -- gamma coincidences are observed in time with the LAMPF beam, with an estimated background of 6.2 events. The 90\% confidence limits obtained are: Delta (m^2) < 0.07eV^2 for sin^2 (2theta) = 1, and sin^2(2theta) < 6 10^{-3} for Delta (m^2) > 20 eV^2.