近日，波兰华沙大学K. Mekala团队研究了Z极第一代夸克耦合的确定。相关论文于2025年11月11日发表在《高能物理杂志》上。

电弱精密测量是对标准模型的严格检验，也是探测新物理的重要探针。对Z玻色子与第一代夸克耦合的精确研究（当前LEP实验数据的精度约为百分之几）可能揭示与理论预言的潜在偏差。未来在Z极点运行的e⁺e^-对撞机将是提升这些约束精度的理想工具。

研究组提出了一种基于上下夸克对Z玻色子辐射与非辐射衰变不同贡献的提取方法。结果证明重味标记性能的系统误差是分析中的关键因素，将其控制在千分之一量级以下对充分发挥未来e⁺e^-对撞机高亮度优势至关重要。该测量有望将LEP实验结果的精度提升至少一个量级。

附：英文原文

Title: Determination of the first-generation quark couplings at the Z-pole

Author: Mkaa, K., Jeans, D., Reuter, J., Tian, J., arnecki, A. F.

Issue&Volume: 2025-11-11

Abstract: Electroweak Precision Measurements are stringent tests of the Standard Model and sensitive probes to New Physics. Accurate studies of the Z-boson couplings to the first-generation quarks, which are currently constrained from LEP data to a few percent, could reveal potential discrepancies from theoretical predictions. Future e+e colliders running at the Z-pole would be an excellent tool to improve these constraints. In this paper, we present a method to extract the values of the Z couplings to light quarks based on up- and down-quarks’ different contributions to radiative and non-radiative Z boson decays. We show that systematic uncertainty in the heavy-flavour tagging performance is the key factor in the analysis, and that reducing it to the sub-permille level is crucial to fully profit from the high luminosity of future e+e machines. The measurement could improve the LEP results by at least an order of magnitude.

DOI: 10.1007/JHEP11(2025)050

Source: https://link.springer.com/article/10.1007/JHEP11(2025)050