IceCube is a cubic-kilometer Cherenkov telescope operating at the South Pole. The main goal of IceCube is the detection of astrophysical neutrinos and the identification of their sources. High-energy muon neutrinos are observed via the secondary muons produced in charge current interactions with nuclei in the ice. Currently, the best performing muon track directional reconstruction is based on a maximum likelihood method using the arrival time distribution of Cherenkov photons registered by the experiment's photomultipliers. A known systematic shortcoming of the prevailing method is to assume a continuous energy loss along the muon track. However at energies >1 TeV the light yield from muons is dominated by stochastic showers. This paper discusses a generalized ansatz where the expected arrival time distribution is parametrized by a stochastic muon energy loss pattern. This more realistic parametrization of the loss profile leads to an improvement of the muon angular resolution of up to 20% for through-going tracks and up to a factor 2 for starting tracks over existing algorithms. Additionally, the procedure to estimate the directional reconstruction uncertainty has been improved to be more robust against numerical errors.

冰立方是在南极运行的立方公里切伦科夫望远镜。IceCube 的主要目标是探测天体物理中微子并确定它们的来源。高能μ子中微子是通过电荷电流与冰中原子核相互作用产生的二次μ子观察到的。目前，性能最好的 μ 子轨道定向重建是基于最大似然方法，使用由实验光电倍增器记录的切伦科夫光子的到达时间分布。现有方法的一个已知系统缺陷是假设沿 μ 子轨道存在连续的能量损失。然而，在能量 > 1 TeV 时，μ 子的光产额由随机阵雨支配。本文讨论了一种广义 ansatz，其中预期到达时间分布由随机 μ 子能量损失模式参数化。与现有算法相比，这种更现实的损耗曲线参数化可将直通轨迹的 μ 子角分辨率提高 20%，并将起始轨迹提高 2 倍。此外，估计方向重建不确定性的程序已得到改进，以对数值误差更加鲁棒。