A Critical Examination on L/E Analysis in the Underground Detectors with a Computer Numerical Experiment Part 1

In the present paper we consider neutrino events due to quasi-elastic scattering (QEL) as the most reliable events among various candidate events to be analyzed, and have carried out the first step of an L/E analysis which aims to confirm the survival probability with a Numerical Computer Experiment. The most important factor in the survival probability is Lnu and Enu, but this cannot be measured for such neutral particles. Instead, Lmu and Emu is utilized in the L/E analysis, where Lnu, Lmu, Enu and Emu denote the flight path lengths of the incident neutrinos, those of the emitted leptons, the energies of the incident neutrinos and those of the emitted leptons, respectively. According to our Computer Numerical Experiment, the relation of Lnu/Enu is nearly equal to Lmu/Emu doesnt hold. In subsequent papers, we show the results on an L/E analysis with the Computer Numerical Experiment based on our results obtained in the present paper.

On the Relation between the True Directions of Neutrinos and the Reconstructed Directions of Neutrinos in L/E Analysis Performed by Super-Kamiokande Collaboration Part2

In the previous paper (Part1), we have verified that the SK assumption on the direction does not hold in the analysis of neutrino events occurred inside the SK detector, which is the cornerstone for their analysis of zenith angle distributions of neutrino events. Based on the correlation between L_nu and L_mu (Figures~16 to 18 in Part1) and the correlation between E_nu and E_mu (Figure19 in Part1), we have made four possible L/E analyses, namely L_nu/E_nu, L_nu/E_mu, L_mu/E_mu and L_mu/E_nu. 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, not only the first maximum oscillation but also the second and third maximum oscillation and etc., as they should be, while the L_mu/E_mu analysis which are really done by Super-Kamiokande Collaboration cannot give any maximum oscillation at all. It is thus concluded from those results that the experiments with the use of the cosmic-ray beam for neutrino oscillation, such as Super-Kamiokande type experiment, are unable to lead the maximum oscillation from their L/E analysis, because the incident neutrino cannot be observed due to its neutrality. Therefore, we would suggest Super-Kamiokande Collaboration to re-analyze the zenith angle distribution of the neutrino events which occur inside the detector carefully, since L_nu and L_mu are alternative expressions of the cosine of the zenith angle for the incident neutrino and that for the emitted muon, respectively.

On the Relation between the True Directions of Neutrinos and the Reconstructed Directions of Neutrinos in L/E Analysis Performed by Super-Kamiokande Collaboration Part1

It should be regarded that the confirmation of the maximum oscillation in neutrino oscillation through L/E analysis by Super-Kamiokande is a logical consequence of their establishment on the existence of neutrino oscillation through the analysis of the zenith angle distribution for atmospheric neutrino events. In the present paper (Part1) with the computer numerical experiment, we examine the assumption made by Super-Kamiokande Collaboration that the direction of the incident neutrino is approximately the same as that of the produced lepton, which is the cornerstone in their L/E analysis, and we find this approximation does not hold even approximately. In a subsequent paper (Part2), we apply the results from Figures 16, 17, 18 and 19 to L/E analysis and conclude that one cannot obtain the maximum oscillation in L/E analysis in the single ring muon events due to quasi-elastic scattering reported by Super-Kamiokande which shows strongly the oscillation pattern from the neutrino oscillation.

On the Capability Of Super-Kamiokande Detector To Define the Primary Parameters Of Muon And Electron Events

We develop a new discrimination procedure for separating electron neutrinos from muon neutrinos, based on detailed simulations carried out with GEANT3.21 and with mean angular distribution functions and their relative fluctuations. Using our procedure we are able to discriminate muons from electrons in Fully Contained Events in Super-Kamioknade Experiment with a probability of error ofless than several %. Also we have checked geometrical resolution on both cases, considering only the ring-like structure of the Cherenkov image and a geometrical reconstruction procedure utilizing the full distribution. Even the methodologically correct approach we have adopted, we cannot reproduce the accuracies for particle discrimination, momentum resolution, interaction vertex location, and angular resolution obtained by the Super-Kamiokande Collaboration.