On the need for unbiasing azimuthal asymmetries in signals measured by surface detector arrays
On the need for unbiasing azimuthal asymmetries in signals measured by surface detector arrays
复制标题
关于表面探测器阵列测量的信号中无偏方位不对称的需要
DOI：
--
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
D. Veberič
中科院分区：
文献类型：
--
作者：
Q. Luce;M. Roth;D. Schmidt;D. Veberič
一个表面探测器阵列在地面上对大面积风淋室（EAS）的横向分布进行采样，即粒子密度作为离风淋室轴线距离的函数。对于具有非零天顶角的EAS，这种测量的横向分布的方位角对称性被打破。由大气衰减和几何效应引起的不对称性随着阵雨的倾斜而增加，并在重建阵雨参数时引入偏差。利用模拟的空气阵雨，我们提出了一个模型来纠正由水切伦科夫探测器测量的信号的方位不对称性，并以皮埃尔奥格天文台的几何和探测器响应为例。利用Epos-LHC和QGSJetII-04作为强子模型，对质子和铁原色引发的阵雨进行了测试，我们建立了一个不对称幅度与天顶角、阵雨大小和探测器与阵雨轴距离的函数关系的精细模型。应用该修正所产生的改进是根据碰撞点和到达方向上的偏差和分辨率来量化的。
A surface detector array samples the lateral distribution of an extensive air-shower (EAS) at the ground, i.e. the density of particles as a function of the distance from the axis of the shower. The azimuthal symmetry of this measured lateral distribution is broken for EAS with a nonzero zenith angle. The resulting asymmetry, caused by atmospheric attenuation and geometrical effects, increases with the inclination of the shower and introduces a bias in the reconstruction of the shower parameters. Using simulated sets of air-showers, we present a model to correct the azimuthal asymmetry in signals measured by water-Cherenkov detectors and exemplified using the geometry and detector response of the Pierre Auger Observatory. Testing showers initiated by proton and iron primaries using Epos-LHC and QGSJetII-04 as hadronic models, we developed a fine-tuned model of the amplitude of the asymmetry as a function of the zenith angle, shower size and distance of a detector from the shower axis. The improvements resulting from the application of the correction are quantified in terms of the biases and resolutions in the impact-point and arrival direction.