CJPL 处使用 1725 m$^{3}$ 液氮探测器对大气中微子振荡的预期灵敏度
Projected Sensitivity to Atmospheric Neutrino Oscillations using a 1725 m$^{3}$ Liquid-Nitrogen Detector at CJPL
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中文总结 AI 辅助
利用CJPL低缪子背景，扩展天顶角范围至cosθ∈[-1,0.3]，基于1725 m³液氮探测器，通过模拟和χ²分析，在10年曝露下显著提高大气中微子振荡灵敏度。
中文摘要 AI 辅助
在大气中微子分析中，可用的天顶角范围通常仅限于上行事件，以抑制宇宙线缪子背景。鉴于中国锦屏地下实验室（CJPL）极低的地下缪子背景，我们研究了扩展天顶角接受范围是否能提高大气中微子振荡测量的灵敏度。采用现有的 1725 m$^{3}$ 液氮体积作为简化探测器模型的基础，其中接受的天顶角范围从 $\cos\theta_{\mu}\in[-1,0]$ 扩展到 $\cos\theta_{\mu}\in[-1,0.3]$，并评估了 10 年曝露下的预期振荡灵敏度。大气中微子通量通过插值标准通量预测作为地磁纬度的函数来估计。对中微子能量 $E\ge0.1$ GeV 的周围岩石和液氮体积中的中微子相互作用进行了模拟，随后进行次级粒子输运和基于几何的事件选择。对于基准振荡参数 $\Delta$m$^{2}_{32}$ = $2.4\times10^{-3}\\ \mathrm{eV}^{2}$ 和 $\sin^{2}\theta_{23}=0.5$，来自周围岩石的中微子诱导缪子通量估计为 $(3.65 \pm 1.00)\times10^{-13}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$，对应于 1725 m$^{3}$ 液氮体积中 $(0.13 \pm 0.034)$ 天$^{-1}$ 的缪子产额。三味中微子振荡被纳入泊松似然 $\chi^{2}$ 分析中，以评估对振荡参数的灵敏度。扩展可用天顶角范围在 10 年曝露下，在 90% 置信水平上导致预期振荡灵敏度的明显改善。
英文摘要
In atmospheric neutrino analyses, the usable zenith-angle range is generally restricted to upward-going events to suppress the cosmic-ray muon background. Motivated by the exceptionally low underground muon background at the China Jinping Underground Laboratory (CJPL), we investigate whether extending the zenith-angle acceptance can improve the sensitivity of atmospheric neutrino oscillation measurements. An existing 1725 m$^{3}$ liquid-nitrogen volume is adopted as the basis of a simplified detector model, in which the accepted zenith-angle range is extended from $\cosθ_μ\in[-1,0]$ to $\cosθ_μ\in[-1,0.3]$, and the projected oscillation sensitivity is evaluated for a 10-year exposure. The atmospheric neutrino flux is estimated by interpolating standard flux predictions as a function of geomagnetic latitude. Neutrino interactions in the surrounding rock and the liquid-nitrogen volume are simulated for neutrino energies of $E\ge0.1$ GeV, followed by secondary-particle transport and geometry-based event selection. For the benchmark oscillation parameters $Δ$m$^{2}_{32}$ = $2.4\times10^{-3}\ \mathrm{eV}^{2}$ and $\sin^{2}θ_{23}=0.5$, the neutrino-induced muon flux from the surrounding rock is estimated to be $(3.65 \pm 1.00)\times10^{-13}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$, corresponding to a muon yield of $(0.13 \pm 0.034)$ day$^{-1}$ in the 1725 m$^{3}$ liquid-nitrogen volume. Three-flavor neutrino oscillations are incorporated into a Poisson-likelihood $χ^{2}$ analysis to evaluate the sensitivity to the oscillation parameters. Extending the usable zenith-angle range leads to a clear improvement in the projected oscillation sensitivity at the 90\% confidence level over a 10-year exposure.
发表机构
- Sichuan University（四川大学）
- Tsinghua University（清华大学）
- Dokuz Eylül University（九月份大学）
机构由 AI 辅助整理，请以论文原文为准。
