发表机构
Chaudhary Charan Singh University; University of Delhi（乔达摩·彻恩·辛格大学; 德里大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究将物质诱导的外在CPT破坏与地球密度分层视为关联系统误差，用单一χ²框架分析其对长基线中微子振荡实验CP相位重建的影响，量化了密度不确定性的作用，提出需联合建模两种效应。
AI 中文摘要
我们对长基线（LBL）中微子振荡实验中的两种物质势系统误差进行了统一分析，将物质诱导的外在CPT破坏和地球密度分层视为单一χ²框架内的关联系统误差，研究它们对CP相位重建及质量排序依赖性的联合影响。物质诱导的外在CPT破坏会产生非零不对称性A_{μe}^{CPT}=(P_{μe}-\bar{P}_{μe})/(P_{μe}+\bar{P}_{μe})，通过对T2K、NOνA、DUNE和Hyper-Kamiokande的精确三味矩阵指数计算得到，该不对称性在各峰值能量处范围为0.022至0.180，正常排序与倒置排序间差异最高达9%。DUNE处的A_{μe}^{CPT}(E,δ_{CP})曲面揭示了高L/E区域中外在CPT破坏与内在CP破坏的相互作用，需进行联合统计处理。我们量化了A_{μe}^{CPT}对密度不确定性ρ→ρ(1+ε)（ε=±1%、±2%、±5%）的灵敏度，发现±5%的不确定性在DUNE处引发|ΔA_{CPT}|<0.008。用恒定路径平均密度替代PREM剖面时，L≤5000km的CP相位重建偏差低于0.3°，在7000km时增至17.8°，12000km时达172.2°。由于两种效应源于同一物质哈密顿量，必须结合泊松对数似然χ²与扰动参数约束进行联合建模。
英文摘要
We present a unified analysis of two matter-potential systematics in long-baseline (LBL) neutrino oscillation experiments. Matter-induced extrinsic CPT violation produces a non-zero asymmetry $A_{μe}^{CPT} = (P_{μe} - P_{\barμ\bar{e}})/(P_{μe} + P_{\barμ\bar{e}})$, computed here with exact three-flavour matrix-exponentiation propagators for T2K, NO$ν$A, DUNE, and Hyper-Kamiokande; values range from 0.022 to 0.180 at the respective peak energies and differ by up to 9\% between normal and inverted mass orderings. The three-dimensional surface $A_{μe}^{CPT}(E, δ_{CP})$ at the DUNE baseline reveals an entanglement between extrinsic CPT violation and intrinsic CP violation in the high-$L/E$ regime that requires joint statistical treatment. Concurrently, replacing the Preliminary Reference Earth Model (PREM) with a constant path-averaged density introduces a $δ_{CP}$-reconstruction bias below $0.3^{\circ}$ for $L \leq 5000$ km but growing to $17.8^{\circ}$ at $L = 7000$ km and $172.2^{\circ}$ at $L = 12000$ km. Since both effects share the same matter-potential Hamiltonian they must be modelled jointly; a Poisson log-likelihood $χ^2$ statistic with nuisance-parameter pull terms is used to quantify the bias.
Comments11 pages, 6 figures
