H→f f̄ V 中的量子比特-量子比特-量子三态量子关联
Qubit-qubit-qutrit quantum correlations in $H \to f \bar f V$
浏览论文内容
中文总结 AI 辅助
该研究分析希格斯衰变h→τ⁻τ⁺Z产生的量子比特-量子比特-量子三态的量子关联，推导贝尔不等式半解析式，扩展魔性至不等维度系统，发现其在相空间非经典区域表现显著非局域魔性。
中文摘要 AI 辅助
我们对由重标量玻色子衰变为费米子-反费米子对和重规范玻色子（H→f f̄ V）产生的量子比特-量子比特-量子三态纯态所携带的量子关联进行了广泛分析，特别针对希格斯玻色子衰变 h→τ⁻τ⁺Z 展开研究。基于精确的树级自旋态及其在无质量费米子极限下的系统展开，我们获得了整个相空间的解析控制：双体纠缠度量、真实的2⊗2⊗3纠缠结构（宫下分类）、贝尔不等式违背以及非稳定子性（魔性）均通过紧凑公式进行了映射和重现。双体度量在费米子对与费米子-玻色子对之间呈现类一夫一妻制的权衡关系。该态在几乎整个相空间中均为真实的2⊗2⊗3纠缠态，在共线区域纠缠最强。我们首次推导了2⊗2⊗3系统的紧4×4×2贝尔不等式的半解析表达式，推广了此前仅适用于三量子比特的优化方法，发现局域隐变量界在整个相空间均被违背，在双τ质量谱的上端点处，其值接近量子界的几个百分点。我们进一步将稳定子 Rényi 熵和非局域魔性扩展到具有不等局域维度的系统，表明近端点态几乎恰好携带1比特的非局域魔性，在共线区域其峰值为 log₂(27/7)≈1.95。微分衰变率恰好集中在相空间的最非经典区域。
英文摘要
We perform an extensive analysis of the quantum correlations carried by the qubit-qubit-qutrit pure state arising in the decay of a massive scalar into a fermion-antifermion pair and a massive gauge boson, $H \to f \bar f V$, specialising to the Higgs boson decay $h \to τ^- τ^+ Z$. Working with the exact tree-level spin state and its systematic expansion around the massless-fermion limit, we obtain analytic control over the entire phase space: the bipartite entanglement measures, the genuine $2 \otimes 2 \otimes 3$ entanglement structure (the Miyake classification), as well as the Bell-inequality violations and the non-stabiliserness (magic) are all mapped and reproduced by compact formulas. The bipartite measures exhibit a monogamy-like trade-off between the fermion pair and the fermion-boson pairs. The state is genuinely $2 \otimes 2 \otimes 3$ entangled over almost the entire phase space, most strongly in the collinear regions. We derive, for the first time, semi-analytical expressions for the tight $4 \times 4 \times 2$ Bell inequalities of the $2 \otimes 2 \otimes 3$ system, generalising the optimisation previously available only for three qubits, and find that the local-hidden-variable bound is violated over the entire phase space, reaching within a few per cent of the quantum bound at the upper endpoint of the di-tau mass spectrum. We further extend the stabiliser Rényi entropy and the non-local magic to systems with unequal local dimensions, and show that the near-endpoint state carries almost exactly one bit of non-local magic, which peaks at $\log_2 \frac{27}{7} \simeq 1.95$ in the collinear regions. The differential decay rate concentrates precisely in the most nonclassical region of the phase space.
