On the Sensitivity of L/E Analysis of Super-Kamiokande Atmospheric Neutrino Data to Neutrino Oscillation Part~2 --- Four Possible L/E Analyses for the Maximum Oscillation by the Numerical Computer Experiment ---

TL;DR

This paper evaluates four different L/E analysis methods for atmospheric neutrino data, concluding that only the neutrino energy and path length ratio accurately reveals maximum oscillations, challenging current Super-Kamiokande practices.

Contribution

The study identifies the most effective L/E analysis method for detecting neutrino oscillation maxima and critiques the assumptions used in existing Super-Kamiokande analyses.

Findings

Only L_nu/E_nu analysis clearly shows maximum oscillation signature.

L_mu/E_mu analysis used by Super-Kamiokande cannot detect maximum oscillation.

Super-Kamiokande should re-analyze zenith angle distributions for accurate results.

Abstract

In the previous paper (Part~1), we have verified that the SK assumption on the direction does not hold in the analysis of neutrino events occurred inside the SK detector. We have made four possible L/E analyses, L_nu/E_nu, L_nu/E_mu, L_mu/E_nu and L_mu/E_mu. Among four kinds of L/E analyses, we have shown that only L_nu/E_nu analysis can give the signature of maximum oscillations clearly, while the L_mu/E_mu analysis which are really done by Super-Kamiokande Collaboration cannot give the maximum oscillation at all. It is thus concluded that Super-Kamiokande type experiment cannot find the maximum oscillation from L/E analysis. Therefore, we would suggest Super-Kamiokande Collaboration to re-analyze the zenith angle distribution of the neutrino events which occur inside the detector carefully.