Compatibility Analysis of the LSND Evidence and the KARMEN Exclusion for numubar->nuebar Oscillations

TL;DR

This paper performs a combined statistical analysis of LSND and KARMEN experiments to assess neutrino oscillation evidence, identifying compatible parameter regions despite conflicting individual results.

Contribution

It introduces a joint likelihood-based analysis with Monte Carlo methods to reconcile LSND and KARMEN neutrino oscillation data.

Findings

Identifies a parameter space region where both experiments are statistically compatible.

Uses a frequentist approach with Monte Carlo simulations for accurate confidence limits.

Provides confidence regions in (sin^2(2theta), Dm^2) parameter space.

Abstract

A combined statistical analysis of the experimental results of the LSND and KARMEN numubar->nuebar oscillation search is presented. LSND has evidence for neutrino oscillations that is not confirmed by the KARMEN experiment. However, there is a region in the (sin^2(2theta),Dm^2) parameter space where the results of both experiments are statistically compatible. This joint analysis is based on likelihood functions for both data sets. A frequentist approach creating Monte Carlo samples analogous to the experimental outcome is applied to deduce correct confidence limits. Different schemes of combination can be chosen to provide correct coverage which lead to slightly different confidence regions in (sin^2(2theta),Dm^2).