地球内核中的异常物质势：暗物质与轻惰性中微子的一种现象学探针

中文摘要 AI 辅助

中微子振荡实验中地球物质效应的标准处理假设，传播中微子所经历的相干前向散射势完全由初步参考地球模型（PREM）所预测的标准模型电子密度提供。我们研究了局域于地球内核的异常物质势（其动机来自引力俘获的暗物质或活性中微子与轻（电子伏特量级或更轻）惰性态之间的共振混合）如何相对于标准模型PREM预期扭曲νμ存活概率和νμ→νe出现概率。使用具有四壳层PREM密度分布的完整三味矩阵指数传播代码，我们将新物理贡献参数化为局限于内核（r<1221 km）的电子扇区势的分数增强εcore，并计算近垂直上行大气中微子（L=8000至12742 km）的振荡概率。不穿过内核的轨迹（L≤12500 km）对εcore基本不敏感，其复现标准模型预期的精度优于0.1%。相比之下，穿过内核的近对跖轨迹（L≥12505 km，对应于天底角在垂直方向约半度以内）显示出显著效应。对于εcore=0.05至0.15，μ子中微子存活概率偏移达数十个百分点，而在特定能量下，νμ→νe出现道的变化超过100%，并伴有明显的中微子-反中微子不对称性，这种不对称性模仿了但物理上不同于固有CP破坏。这些结果表明，局限于内核的百分之一量级新物理势处于高统计量大气中微子望远镜（如IceCube Upgrade、KM3NeT/ORCA以及下一代百万吨级探测器）的发现能力范围内。

英文摘要

Standard treatments of Earth matter effects in neutrino oscillation experiments assume that the coherent forward scattering potential experienced by propagating neutrinos is sourced entirely by the Standard Model electron density predicted by the Preliminary Reference Earth Model (PREM). We examine how an anomalous matter potential localized in Earth's inner core, motivated by gravitationally captured dark matter or resonant mixing of active neutrinos with a light (eV-scale or lighter) sterile state, would distort the vu survival and vutove appearance probabilities relative to the Standard Model PREM expectation. Using a full three-flavor matrix-exponentiation propagation code with a four-shell PREM density profile, we parametrize the new-physics contribution as a fractional enhancement ecore of the electron-sector potential confined to the inner core (r<1221 km) and compute oscillation probabilities for near-vertically upgoing atmospheric neutrinos (L=8000to12742km). Trajectories that do not cross the inner core (L<=12500km) are essentially insensitive to ecore, reproducing the Standard Model expectation to better than 0.1%. In contrast, near-antipodal trajectories crossing the inner core (L>=12505km, corresponding to nadir angles within roughly half a degree of the vertical) show significant effects. The muon-neutrino survival probability is displaced by tens of percent for ecore=0.05to0.15 and by more than 100% at particular energies for the νμ to νe appearance channel, with a pronounced neutrinoantineutrino asymmetry that mimics, but is physically distinct from, intrinsic CP violation. These results indicate that percent-level new-physics potentials confined to the inner core are within the discovery reach of high-statistics atmospheric neutrino telescopes such as IceCube Upgrade, KM3NeT/ORCA, and next-generation megaton-scale detectors.

发表机构

• University of Delhi（德里大学）
• Chaudhary Charan Singh University（乔杜里·查兰·辛格大学）

机构由 AI 辅助整理，请以论文原文为准。