Scholarlink

<p>Electroweak Precision Measurements are stringent tests of the Standard Model and sensitive probes to New Physics. Accurate studies of the <i>Z</i>-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 <i>e</i><sup>+</sup><i>e</i><sup>−</sup> colliders running at the <i>Z</i>-pole would be an excellent tool to improve these constraints. In this paper, we present a method to extract the values of the <i>Z</i> couplings to light quarks based on up- and down-quarks’ different contributions to radiative and non-radiative <i>Z</i> 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 <i>e</i><sup>+</sup><i>e</i><sup>−</sup> machines. The measurement could improve the LEP results by at least an order of magnitude.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

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

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年11月11日

查看全文
  • K. Mękała,
  • D. Jeans,
  • J. Reuter,
  • J. Tian,
  • A. F. Żarnecki

摘要

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.