Systematic analysis of the determination of the value of leptonicCP-violating angle delta and the neutrino mass hierarchy sgn(delta m^2_31) bylong baseline neutrino oscillation experiments is presented. We note thedifficulty to distinguish a pair of oscillation probability spectra that arepeaked at the same energy and have the same probability at that energy. Wethereby set forth the peak-matching condition as a criterion of the presence ofdegeneracy, and visualize it by intersections of the trajectories drawn by apeak of an oscillation spectrum while the value of delta is varied from 0 to2pi. We numerically calculate the pairs of the trajectories for bothhierarchies and show that the pair becomes disjoint as the baseline gets longerthan a critical length, indicating the matter effect resolving the degeneracyon the hierarchy. We formulate the trajectories into analytic expressions andevaluate the critical length. We provide prospects of the following fourapproaches of resolving the hierarchy: making the baseline longer than thecritical length, using both neutrinos and anti-neutrinos, combining experimentswith different baseline lengths, and observing two or more oscillation peaks.
展开▼
机译：提出了通过长期基线中微子振荡实验确定轻子CP违规角δ值和中微子质量层次sgn（delta m ^ 2_31）的系统分析。我们注意到难以区分以相同能量说话且在该能量下具有相同概率的一对振荡概率谱。因此，我们将峰值匹配条件设定为存在简并性的标准，并通过在δ值从0变为2pi时通过振荡频谱的峰值绘制的轨迹的交点将其可视化。我们用数值方法计算了两个层次的轨迹对，并表明随着基线超过临界长度，该对轨迹变得不相交，表明物质效应解决了层次上的退化。我们将轨迹公式化为解析表达式，并评估临界长度。我们提供了以下四种解决层次的方法的前景：使基线长于临界长度，同时使用中微子和反中微子，结合具有不同基线长度的实验，并观察两个或多个振荡峰。
展开▼
