[Paper Review] Configurations of the Long-Baseline Neutrino Experiment

V. Barger, Atri Bhattacharya+4 more|arXiv (Cornell University)|May 5, 2014

Neutrino Physics Research3 citations

TL;DR

This paper evaluates the Long-Baseline Neutrino Experiment (LBNE) for resolving key neutrino physics questions, including mass hierarchy, octant of θ₂₃, and CP violation, using beam and atmospheric neutrino data. With a 35 kt detector and near detector, LBNE can resolve the eight-fold degeneracy inherent in long-baseline experiments and achieve its primary physics goals.

ABSTRACT

We perform a comprehensive study of the ability of the Long-Baseline Neutrino Experiment (LBNE) to answer outstanding questions in the neutrino sector. We consider the sensitivities to the mass hierarchy, the octant of $ heta_{23}$ and to CP violation using data from beam and atmospheric neutrinos. We evaluate the dependencies on the precision with which $ heta_{13}$ will be measured by reactor experiments, on the detector size, beam power and exposure time, on detector magnetization, and on the systematic uncertainties achievable with and without a near detector. We find that a 35 kt LBNE with a near detector will resolve the eight-fold degeneracy that is intrinsic to long baseline experiments and will meet the primary goals of oscillation physics that it is designed for.

Motivation & Objective

• To assess LBNE's sensitivity to the neutrino mass hierarchy using beam and atmospheric neutrino data.
• To investigate the experiment's ability to determine the octant of the mixing angle θ₂₃.
• To evaluate CP violation sensitivity in the neutrino sector using long-baseline measurements.
• To examine the impact of reactor-measured θ₁₃ precision, detector size, beam power, exposure time, magnetization, and systematic uncertainties.
• To determine whether LBNE can resolve the intrinsic eight-fold degeneracy in long-baseline neutrino oscillation experiments.

Proposed method

• Perform a comprehensive simulation-based study of neutrino oscillation sensitivities using beam and atmospheric neutrino events.
• Vary key experimental parameters: detector size (35 kt), beam power, exposure time, and presence of a near detector.
• Assess the effect of detector magnetization on sensitivity to CP violation and mass hierarchy.
• Incorporate systematic uncertainties with and without a near detector to evaluate their impact on sensitivity.
• Use the measured value of θ₁₃ from reactor experiments as a constraint in the analysis.
• Evaluate the resolution of the eight-fold degeneracy through statistical analysis of oscillation parameters.

Experimental results

Research questions

• RQ1 Can LBNE resolve the eight-fold degeneracy in neutrino oscillation parameters inherent to long-baseline experiments?
• RQ2 How does the inclusion of a near detector affect the sensitivity to mass hierarchy, octant, and CP violation?
• RQ3 What is the required detector size and beam power to achieve the primary physics goals of LBNE?
• RQ4 How do systematic uncertainties influence the sensitivity to CP violation and mass hierarchy?
• RQ5 How does the precision of θ₁₃ from reactor experiments affect the overall sensitivity of LBNE?

Key findings

• A 35 kt LBNE detector with a near detector can resolve the eight-fold degeneracy that is intrinsic to long-baseline neutrino experiments.
• The inclusion of a near detector significantly improves the sensitivity to the neutrino mass hierarchy and the octant of θ₂₃.
• LBNE with a 35 kt detector and near detector achieves the primary physics goals of oscillation physics, including sensitivity to CP violation.
• Systematic uncertainties have a measurable impact, but their effect is mitigated with the addition of a near detector.
• The precision of θ₁₃ from reactor experiments is a key input that influences the overall sensitivity of LBNE.
• Beam power and exposure time are critical factors in achieving high sensitivity to CP violation and mass hierarchy.