超越$X_\text{max}$：利用SKA-Low的信息场论重建空气簇射轮廓
Beyond $X_\mathrm{max}$ : Reconstructing Air Shower Profiles with Information Field Theory with SKA-Low
AI总结：
本研究提出基于信息场论的重建框架，结合Gaisser-Hillas轮廓、SMIET等，从SKA-Low类无线电测量中恢复空气簇射完整轮廓，实现高精度参数重建，为研究簇射强子物理及质量成分提供支撑。
AI中文摘要：
尽管甚高能空气簇射的无线电测量已被证明能实现$X_\text{max}$的高灵敏度，但研究表明，$X_\text{max}$之外的参数也可被重建。这些形状参数包含对簇射强子物理及其质量成分的额外灵敏度。本研究展示了一种从真实无线电测量中恢复完整纵向轮廓的重建框架，该框架基于信息场论，通过正向模型推断完整轮廓，正向模型采用带有弱信息簇射先验的Gaisser-Hillas轮廓、结合模板库的SMIET以合成任意事件几何下的脉冲，以及模拟SKA-Low的真实天线响应与噪声水平。我们用SMIET生成的约900个事件验证了框架的自洽性，这些事件的天线均放置在$\boldsymbol{v} \times (\boldsymbol{v} \times \boldsymbol{B})$轴上。该框架在不确定度范围内恢复了完整轮廓，并捕捉到簇射参数间的相关性，实现了$X_\text{max}$分辨率小于9 g cm$^{-2}$，且宽度与不对称性的分辨率偏差极小；在所有小于1200 g cm$^{-2}$的大气深度下，轮廓恢复偏差均小于4%。我们计划将该框架应用于带有实测噪声的CoREAS模拟脉冲，最终将其扩展至LOFAR或SKA-Low等真实天线布局。
英文摘要：
While radio measurements of extensive air showers have shown to achieve a high precision of $X_\mathrm{max}$ sensitivity, it has been shown that parameters beyond $X_\mathrm{max}$ can also be reconstructed. These shape parameters contain additional sensitivity to the hadronic physics in the shower as well as its mass composition. In this work, we showcase a reconstruction framework to recover the full longitudinal profile from realistic radio measurements. The framework is based on Information Field Theory that infers the full profile with a forward-based model, which uses a Gaisser-Hillas profile with weakly informative shower priors, SMIET with a template library to synthesise pulses at any event geometry, and a realistic antenna response and noise level emulating that of SKA-Low. We verify the self-consistency of our framework with $\sim 900$ events generated with SMIET with antennas placed on the $\vec{v} \times (\vec{v} \times \vec{B})$ axis. The framework recovers the full profile within uncertainty and capture correlations between shower parameters. We yield an $X_\mathrm{max}$ resolution of $< 9$ g cm$^{-2}$ as well as resolutions of the width and asymmetry with minimal bias. The profile is also recovered with a bias of $< 4$% at all atmospheric depths $< 1200$ g cm$^{-2}$. We aim to apply this framework with pulses simulated from CoREAS with measured noise, ultimately extending the framework to realistic antenna layouts such as from LOFAR or SKA-Low.
