A new three-dimensional track fit with multiple scattering-猫眼课题宝

一种具有多重散射的新型三维轨道拟合

DOI：

10.1016/j.nima.2016.11.012

发表时间：

2017

期刊：

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment

影响因子：

1.4

通讯作者：

中科院分区：

物理与天体物理3区

文献类型：

作者：

N. Berger;M. Kiehn;A. Kozlinskiy;A. Schöning

现代半导体探测器允许带电粒子跟踪，并且位置分辨率不断提高。由于空间命中不确定性的减少，探测器层中的多重库仑散射成为跟踪不确定性的主要来源。在这种情况下，对于动量测量，可以忽略长距离效应，并且轨迹拟合可以因此被公式化为击中三联体的独立拟合之和。在本文中，我们提出了基于多重散射模型的均匀磁场中三维三元组拟合的解析解。使用线性化 ansatz 执行命中三元组的轨迹拟合。讨论了典型光谱仪设置的动量分辨率。此外，该轨迹拟合与两种不同像素探测器几何形状的其他轨迹拟合进行了比较，即 PSI 的 Mu3e 实验和典型的高能对撞机实验。对于大动量范围，三联体拟合比单螺旋拟合提供了明显更好的性能。三元组拟合速度快，并且可以轻松并行化，这使其成为并行计算架构上实现的理想选择。

Modern semiconductor detectors allow for charged particle tracking with ever increasing position resolution. Due to the reduction of the spatial hit uncertainties, multiple Coulomb scattering in the detector layers becomes the dominant source for tracking uncertainties. In this case long distance effects can be ignored for the momentum measurement, and the track fit can consequently be formulated as a sum of independent fits to hit triplets. In this paper we present an analytical solution for a three-dimensional triplet(s) fit in a homogeneous magnetic field based on a multiple scattering model. Track fitting of hit triplets is performed using a linearization ansatz. The momentum resolution is discussed for a typical spectrometer setup. Furthermore the track fit is compared with other track fits for two different pixel detector geometries, namely the Mu3e experiment at PSI and a typical high-energy collider experiment. For a large momentum range the triplets fit provides a significantly better performance than a single helix fit. The triplets fit is fast and can easily be parallelized, which makes it ideal for the implementation on parallel computing architectures.