味分辨四费米子探针在FCC-ee $Z$极点处的研究
Flavor-resolved four-fermion probes at the FCC-ee $Z$ pole
- Institute for Advanced Research, Nagoya University（名古屋大学高等研究院）
- Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University（名古屋大学小林-益川粒子宇宙起源研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
研究FCC-ee $Z$极点处味分辨四体过程，探测味特异新物理接触相互作用，获得多TeV灵敏度，并补充电弱精密测量。
AI中文摘要：
正负电子未来环形对撞机将在$Z$极点处提供前所未有的精密研究机会。除了改进在LEP上开创的电弱测量外，Tera-$Z$统计量和现代喷注味重建可使稀有的、味分辨的终态作为精密观测量变得可及。我们研究了排他的四体过程$e^+e^-\to Z\to Q\bar Q\ell^+\ell^-$，其中$Q=c,\\,b$且$\ell=\mu,\\,\tau$，作为味特异新物理接触相互作用的探针。快速分析给出了涉及底或粲夸克与缪子或陶子的矢量流相互作用的代表性多TeV可达范围，为未来探测器级研究提供了基线。对于粲流相互作用，预期的直接灵敏度与从电弱精密观测量间接获得的灵敏度相当。二维拟合进一步表明，这些过程保留了夸克味信息，而重整化群诱导的电弱响应难以分辨这些信息。这些结果展示了味分辨四体$Z$过程如何在FCC-ee上连接电弱与味物理项目，开启了一类新的互补精密观测量。
英文摘要：
The electron-positron Future Circular Collider will provide an unprecedented opportunity for precision studies at the $Z$ pole. In addition to improving the electroweak measurements pioneered at LEP, Tera-$Z$ statistics and modern jet flavor reconstruction could make rare, flavor-resolved final states accessible as precision observables. We study the exclusive four-body processes $e^+e^-\to Z\to Q\bar Q\ell^+\ell^-$ with $ Q=c,\,b$ and $\ell=μ,\,τ$ as probes of flavor-specific new physics contact interactions. A fast analysis yields representative multi-TeV reaches for vector-current interactions involving bottom or charm quarks and muons or taus, providing a baseline for future detector-level studies. For charm-current interactions, the projected direct sensitivities are comparable to those obtained indirectly from electroweak precision observables. Two-dimensional fits further show that these processes retain quark-flavor information that can be poorly resolved by the renormalization-group-induced electroweak response. These results illustrate how flavor-resolved four-body $Z$ processes can bridge the electroweak and flavor programs at FCC-ee, opening a new class of complementary precision observables.
