AI 中文总结
研究如何在$t\bar{t}$对量子态中编码新的CP违反顶夸克相互作用，推导产生密度矩阵解析表达式，识别CP奇结构，构建可观测量并研究量子信息度量响应，评估其对CP破坏源的敏感性，建立产生水平框架。
AI 中文摘要
我们研究了新的可能违反CP的顶夸克相互作用如何编码在产生的$t\bar{t}$对的量子态中。我们推导了与强子、轻子和光子对撞机相关的几个基准通道中产生密度矩阵的解析表达式。在一个共同的自旋基中，我们在Fano-Bloch分解中识别出两个特征性的CP奇结构：顶夸克和反顶夸克极化矢量之间的差异以及自旋相关矩阵的反对称分量。我们构建了直接探测这些结构的可观测量，并研究了包括量子失协、并发度、魔术和迹距离在内的量子信息度量如何响应CP偶和CP奇的SMEFT贡献。最后，利用当前测量和未来对撞机的预测，我们评估了这些可观测量对顶夸克产生中可能的新CP破坏源的敏感性。这建立了一个产生水平的框架，其实验重建在一篇配套论文中展开。
英文摘要
We investigate how possible new CP-violating top-quark interactions are encoded in the quantum state of a produced $t\bar t$ pair. We derive analytic expressions for the production density matrix in several benchmark channels relevant to hadron, lepton and photon colliders. In a common spin basis, we identify two characteristic CP-odd structures in the Fano--Bloch decomposition: a difference between the top and antitop polarisation vectors and an antisymmetric component of the spin-correlation matrix. We construct observables that directly probe these structures and study how quantum information measures, including discord, concurrence, magic and trace distance, respond to CP-even and CP-odd SMEFT contributions. Finally, using current measurements and future collider projections, we assess the sensitivity of these observables to possible new sources of CP violation in top-quark production. This establishes the production-level framework whose experimental reconstruction is developed in a companion paper.
Comments70 pages, 24 figures
