Track reconstruction using a 3-D map of the target magnetic field-猫眼课题宝

使用目标磁场的 3D 地图进行轨迹重建

DOI：

10.1016/j.nima.2008.09.007

发表时间：

2008-12

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：

Zhu, Bo;Ye, Hong-xue;Mao, Ya-jun;Wang, Si-guang

磁场经常应用于粒子束的靶区，以保持气态目标的极化，就像Hermes实验一样。然而，同样的磁场会使带电粒子的轨迹弯曲，从而在顶点重建中引入误差。本文描述了一种精确描述三维非均匀磁场中相对论带电粒子输运的方法。在Hermes实验数据上对该算法进行了测试，结果表明，该算法显著改善了π+π不变质谱图中的Ks0共振。事实上，目标磁铁开启时采集的校正数据与关闭磁铁时采集的数据一样好。给出了目标区域的三维磁场图，该方法可以很容易地应用于其他实验。相关代码在附录中提供。

Magnetic fields are often applied to the target zone of a particle beam to maintain the polarization of gaseous targets, as with the HERMES experiment. The same field bends the trajectories of charged particles, however, introducing errors in vertex reconstruction. This paper describes a method for accurately describing relativistic charged particle transport within a 3-dimensional (3-D), non-uniform magnetic field. The algorithm is tested on HERMES experimental data, and is shown to substantially improve the Ks0resonance in the π+π-invariant mass spectrum. Indeed, corrected data taken with target magnet switched on are as good as data taken with magnet switched off. The method can easily be applied to other experiments given a 3-D magnetic field map of the target region. The relevant code is provided in an Appendix.