Calculation and experimental analysis of the muon cross sections

μ子在中微子天文学和宇宙射线物理学领域的天体粒子物理学中被用作最终信使粒子。因此，μ介子的相互作用几率正在进入天体物理学相关数据的解释，即中微子能谱的确定对于回答大气、瞬发和天体物理中微子的贡献及其起源的问题非常重要。由于IceCube记录的μ子速率很高（统计精度很高），现有μ子截面计算的系统不确定性大大增加了实验的系统不确定性。这些新的横截面应在应用小组开发的Monte Carlo算法PROPOSAL中实施，以确定剩余不确定性的实验结果。在这方面，已经可以证明，要最小化的系统不确定性的相关贡献来自μ子能量损失的概率分布，而不是来自总的相互作用概率。同时，IceCube记录的大气和中微子诱导μ子的独立数据集将用于测试截面计算的质量，分别尽可能地重建截面。该项目基于申请组在计算科学和统计学领域的大量预备研究（信号提取的数据挖掘，逆问题解决方法的开发，蒙特卡罗模拟的有效方法的开发）和实验和理论物理学领域（用于重建IceCube中轻子谱的数据分析，开发用于计算截面的QED方法）。该项目的目标是在三年后显着改善微分和总μ子截面，其不确定性应通过数值和实验手段进行量化。

Muons are used as final messenger particles in astroparticle physics on the fields of neutrino astronomy and cosmic ray physics. Therefore, the interaction probability of muons is entering the interpretation of the astrophysical relevant data, i.e. the determination of neutrino energy spectra important to answer the question for the contributions of atmospheric, prompt and astrophysical neutrinos and their origin. Because of the high muon rate recorded with IceCube (high statistical precision), the this-exceeding systematic uncertainties from the existing calculations of the muon cross sections are contributing significantly to the total systematic uncertainty of the experiment.In this project, on the one hand the muon cross sections shall be calculated with means of theoretical physics to a higher precision. These new cross sections shall be implemented in the Monte Carlo algorithm PROPOSAL, developed by the applying group, to determine the experimental consequences of the remaining uncertainties. In this regard, it could already be shown, that the relevant contributions to the systematic uncertainty to be minimized are coming from the probability distribution of the muon energy losses rather than from the total interaction probability. In parallel, the independent data sets of the atmospheric and neutrino induced muons recorded with IceCube shall be used to test the quality of the cross section calculations, respectively to reconstruct the cross section as far as possible.The project is based on a multitude of preparatory studies of the applying group from the fields of computational science and statistics (data mining for the signal extraction, development of methods for the solution of inverse problems, development of efficient methods for the Monte Carlo simulation) and from the fields of experimental and theoretical physics (data analyses for the reconstruction of the lepton spectra in IceCube, development of methods for the QED calculation of the cross sections).The project aims after three years for a significant improvement of the differential and total muon cross sections, whose uncertainties shall be quantified with numerical and experimental means.