arXiv 1306.14232013-06-06hep-ph

用μ子和强子事件测量大气中微子实验中的质量等级

Measuring the Mass Hierarchy with Muon and Hadron Events in Atmospheric Neutrino Experiments

Anushree Ghosh, Sandhya Choubey

备注：: 29 pages
DOI：: 10.1007/JHEP10(2013)174

摘要：

在大气中微子实验中，可以通过观测地球物质效应来测量中微子质量等级。磁化铁量热计由于其电荷识别能力而在这方面表现良好。在这个探测器中，$ν_μ$的带电电流相互作用产生了μ子径迹和强子簇射。μ子轨道的方向可以非常精确地测量。我们显示了预期的改善，达到这类实验的中微子质量层次，因为我们提高了μ子能量分辨率和μ子重建效率。接下来，我们建议在分析中包括强子事件，通过用相应μ子的天顶角标记它们，并首先在能量上然后在天顶角上合并强子数据。据我们所知，这种对大气中微子数据进行分析的方法以前从未被考虑过。我们表明，强子事件增加了实验的质量层次的灵敏度。最后，我们显示了预期的质量层次的灵敏度重建中微子能量和天顶角。我们展示了探测器的分辨率如何破坏中微子通道中的地球物质效应，并论证了为什么从中微子分析中获得的灵敏度不能明显优于仅使用μ子数据的分析。结果表明，当我们把μ子和强子数据的贡献相加时，得到了最佳的质量等级灵敏度。对于$\sin^22θ_{13}=0.1$，$\sin^2θ_{23}=0.5$，μ子能量分辨率为2%，重建效率为80%，曝光量为$50\times 10$ k吨-年，通过结合μ子和强子的数据，我们可以得到质量等级的$4.5σ$信号。

英文摘要：

Neutrino mass hierarchy can be measured in atmospheric neutrino experiments through the observation of earth matter effects. Magnetized iron calorimeters have been shown to be good in this regard due to their charge identification capabilities. The charged current interaction of $ν_μ$ in this detector, produces a muon track and a hadron shower. The direction of the muon track can be measured very accurately. We show the improvement expected in the reach of this class of experiments to the neutrino mass hierarchy, as we improve the muon energy resolution and the muon reconstruction efficiency. We next propose to include the hadron events in the analysis, by tagging them with the zenith angle of the corresponding muon and binning the hadron data first in energy and then in zenith angle. To the best of our knowledge this way of performing the analysis of the atmospheric neutrino data has not be considered before. We show that the hadron events increase the mass hierarchy sensitivity of the experiment. Finally, we show the expected mass hierarchy sensitivity in terms of the reconstructed neutrino energy and zenith angle. We show how the detector resolutions spoil the earth matter effects in the neutrino channel and argue why the sensitivity obtained from the neutrino analysis cannot be significantly better than that obtained from the analysis using muon data alone. As a result, the best mass hierarchy sensitivity is obtained when we add the contribution of the muon and the hadron data. For $\sin^22θ_{13}=0.1$, $\sin^2θ_{23}=0.5$, a muon energy resolution of 2\%, reconstruction efficiency of 80\% and exposure of $50\times 10$ kton-year, we could get up to $4.5σ$ signal for the mass hierarchy from combining the muon and hadron data.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文