论文标题
高能物理实验中螺旋颗粒轨迹重建的近似方法
Approximate method for helical particle trajectory reconstruction in high energy physics experiments
论文作者
论文摘要
高能物理实验，特别是在LHC上进行的实验，需要重建带电的颗粒轨迹。重建此类轨迹的方法已知数十年，但是高光度LHC的应用要求此重建足够快，以适合在线活动过滤。 遍历检测器体积的粒子在活跃的检测器元素中留下信号，从中重建轨迹。如果检测器浸入轨迹均匀的磁场中，则近似螺旋。由于碰撞事件会导致许多颗粒的产生，尤其是在高亮度下的产生，因此轨迹重建的第一阶段是由少量检测器测量值组成的候选轨迹的形成，然后是资源密集型精确轨迹参数估计的对象。 在本文中，我们建议一种可以用来执行此分类的新方法。提出的过程除了垂直于磁场方向的平面中的$ x，y $坐标外，还利用了$ z $坐标。建议的算法对于与光束线的近端不同的螺旋轨迹同样效果，这在搜索寿命较长的颗粒产品时是有益的。
High energy physics experiments, in particular experiments at the LHC, require the reconstruction of charged particle trajectories. Methods of reconstructing such trajectories have been known for decades, yet the applications at High Luminosity LHC require this reconstruction to be fast enough to be suitable for online event filtering. A particle traversing the detector volume leaves signals in active detector elements from which the trajectory is reconstructed. If the detector is submerged in a uniform magnetic field that trajectory is approximately helical. Since a collision event results in the production of many particles, especially at high luminosities, the first phase of trajectory reconstruction is the formation of candidate trajectories composed of a small subset of detector measurements that are then subject of resource intensive precise track parameters estimation. In this paper, we suggest a new approach that could be used to perform this classification. The proposed procedure utilizes the $z$ coordinate in the longitudinal direction in addition to the $x, y$ coordinates in the plane perpendicular to the direction of the magnetic field. The suggested algorithm works equally well for helical trajectories with different proximities to the beamline which is beneficial when searching for products of particles with longer lifetimes.
