标题： 系统可解释性与提升顶夸克识别的可能性 显示英文标题

标题： Systematic Interpretability and the Likelihood for Boosted Top Quark Identification

摘要： 对具有高能、强子衰变的顶夸克的识别是大型强子对撞机物理目标中的核心问题。 我们对顶夸克标记进行理论分析，确立任何所谓的顶夸克标记喷注应满足的零阶最小假设，如存在三个硬次级喷注、一个底夸克标记的次级喷注、总质量与顶夸克一致，以及成对次级喷注质量与W玻色子一致。 从这些最小假设出发，我们构建了最优的区分可观测量，即在强耦合常数的下一阶近似下，用于区分由顶夸克和底夸克引发的喷注的似然比。 我们比较并计算了信号和背景效率，既通过解析方法也通过模拟数据，验证了对似然所识别和利用的相关物理的理解。 在此过程中，我们构建了一种对此问题似然比的系统可解释方法，并明确建立了可能区分能力的硬下限。 这些结果可以相应地应用于理解与解释对此问题的机器学习研究。 显示英文摘要

摘要： Identification of boosted, hadronically-decaying top quarks is a problem of central importance for physics goals of the Large Hadron Collider. We present a theoretical analysis of top quark tagging, establishing zeroth-order, minimal assumptions that should be satisfied by any purported top-tagged jet, like existence of three hard subjets, a bottom-tagged subjet, total mass consistent with the top quark, and a pairwise subjet mass consistent with the W boson. From these minimal assumptions, we construct the optimal discrimination observable, the likelihood ratio, for the binary discrimination problem of top quark-initiated versus bottom quark-initiated jets through next-to-leading order in the strong coupling. We compare and compute corresponding signal and background efficiencies both analytically and from simulated data, validating an understanding of the relevant physics identified and exploited by the likelihood. In the process, we construct a method for systematic interpretability of the likelihood ratio for this problem, and explicitly establish a hard floor on possible discrimination power. These results can correspondingly be applied to understanding and interpreting machine learning studies of this problem.