标题： 用MGMR3D重建空气簇射参数 显示英文标题

标题： Reconstructing Air Shower Parameters with MGMR3D

摘要： 测量宇宙射线粒子级联产生的无线电发射已被证明是一种非常有效的方法，用于确定其特性，如质量组成。 高效模拟空气簇射的无线电发射对于从测得的无线电发射中提取宇宙射线物理参数至关重要。 MGMR3D 是一个快速的半解析代码，能够计算参数化 Shower-Current 密度的完整无线电足迹，即强度、极化和脉冲形状，并可用于卡方优化以拟合给定的无线电数据。 它比其蒙特卡洛对应方法快多个数量级。 我们提供了 MGMR3D 与蒙特卡洛模拟的详细比较研究，在此研究中，通过改进的参数化方法，发现簇射最大值$\Xmax$与入射天顶角的依赖性很小，具有非常强的一致性。 我们用 MGMR3D 观察到的另一个有趣特性是，除了$\Xmax$外，对纵向剖面的形状也具有敏感性。 这是通过探测由具有不同于通常情况的纵向剖面的簇射产生的可区分的无线电足迹来实现的。 此外，我们首次展示了使用 MGMR3D 对 LOFAR 数据进行簇射参数重建的结果，并获得了$\Xmax$的分辨率 22 g/cm$^2$和能量分辨率 19%。 显示英文摘要

摘要： Measuring the radio emission from cosmic ray particle cascades has proven to be a very efficient method to determine their properties such as the mass composition. Efficient modeling of the radio emission from air showers is crucial in order to extract the cosmic ray physics parameters from the measured radio emission. MGMR3D is a fast semi-analytic code that calculates the complete radio footprint, i.e.\ intensity, polarization, and pulse shapes, for a parametrized shower-current density and can be used in a chi-square optimization to fit a given radio data. It is many orders of magnitude faster than its Monte Carlo counterparts. We provide a detailed comparative study of MGMR3D to Monte Carlo simulations, where, with improved parametrizations, the shower maximum $\Xmax$ is found to have very strong agreement with a small dependency on the incoming zenith angle of the shower. Another interesting feature we observe with MGMR3D is sensitivity to the shape of the longitudinal profile in addition to $\Xmax$. This is achieved by probing the distinguishable radio footprint produced by a shower having a different longitudinal profile than usual. Furthermore, for the first time, we show the results of reconstructing shower parameters for LOFAR data using MGMR3D, and obtaining a $\Xmax$ resolution of 22 g/cm$^2$ and energy resolution of 19\%.