Optimizing the Determination of the Neutrino Mixing Angle ${\theta }_{13}$ from Reactor Data

Abstract

The technical breakthroughs of multiple detectors developed by Daya Bay and RENO collaborations have gotten great attention. Yet the optimal determination of neutrino mixing parameters from reactor data depends on the statistical method and demands equal attention. We find that a straightforward method using a minimal parameters will generally outperform a multi-parameter method by delivering more reliable values with sharper resolution. We review standard confidence levels and statistical penalties for models using extra parameters, and apply those rules to our analysis. We find that the methods used in recent work of the Daya Bay and RENO collaborations have several undesirable properties. The existing work also uses non-standard measures of significance which we are unable to explain. A central element of the current methods consists of variationally fitting many more parameters than data points. As a result the experimental resolution of ${\sin }^2(2{\theta }_{13})$ is degraded. The results also become extremely sensitive to certain model parameters that can be adjusted arbitrarily. The number of parameters to include in evaluating significance is an important issue that has generally been overlooked. The measures of significance applied previously would be consistent if and only if all parameters but one were considered to have no physical relevance for the experiment's hypothesis test. Simpler, more transparent methods can improve the determination of the mixing angle ${\theta }_{13}$ from reactor data, and exploit the advantages from superb hardware technique of the experiments. We anticipate that future experimental analysis will fully exploit those advantages.

New text, new figure and new references revise the thrust of the paper to improve determination of the mixing angle. New title reflects this improvement

References in corpus (9)

• Observation of electron-antineutrino disappearance at Daya Bay
• Observation of Reactor Electron Antineutrino Disappearance in the RENO Experiment
• Indication of Electron Neutrino Appearance from an Accelerator-produced Off-axis Muon Neutrino Beam
• Indication for the disappearance of reactor electron antineutrinos in the Double Chooz experiment
• Improved search for muon-neutrino to electron-neutrino oscillations in MINOS
• Reactor electron antineutrino disappearance in the Double Chooz experiment
• Improved Measurement of Electron Antineutrino Disappearance at Daya Bay
• Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay
• First Measurement of θ_13 from Delayed Neutron Capture on Hydrogen in the Double Chooz Experiment

Cited by in corpus (1)

• Extraction of neutrino mixing parameters from experiments with multiple identical detectors