Limits on Electron Neutrino Disappearance from the KARMEN and LSND electron neutrino - Carbon Cross Section Data

TL;DR

This study combines KARMEN and LSND electron neutrino-carbon cross section data to set stringent limits on electron neutrino disappearance at high Delta m^2, challenging some previous oscillation claims.

Contribution

It provides a combined analysis of two experiments' data to constrain electron neutrino disappearance, excluding most of the previously allowed parameter space at high Delta m^2.

Findings

Most of the Gallium anomaly region is excluded at >95% CL.

The best-fit oscillation point is excluded at 3.6 sigma.

Limits are consistent with CPT conservation assumptions.

Abstract

This paper presents a combined analysis of the KARMEN and LSND nu_e-carbon cross section measurements within the context of a search for nu_e disappearance at high Delta m^2. KARMEN and LSND were located at 17.7 m and 29.8 m respectively from the neutrino source, so the consistency of the two measurements, as a function of antineutrino energy, sets strong limits on neutrino oscillations. Most of the allowed region from the nu_e disappearance analysis of the Gallium calibration data is excluded at >95% CL and the best fit point is excluded at 3.6$\sigma$. Assuming CPT conservation, comparisons are also made to the oscillation analyses of reactor antineutrino data.