Mixed Strong--Electroweak Radiative Corrections the Production of W/Z Bosons at the LHC

混合强电弱辐射校正大型强子对撞机中 W/Z 玻色子的产生

• 批准号: 414714711
• 负责人: Professor Dr. Stefan Dittmaier
• 金额: --
• 依托单位: Physikalisches Institut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/414714711?language=en
• 关键词: Mixed; Strong; Electroweak; Radiative; Corrections

The Drell-Yan-like production of W and Z bosons is among the most important classes of particle reactions at the CERN Large Hadron Collider (LHC). As standard candle processes they are used in detector calibration, they offer high-precision measurements of the effective weak mixing angle and the W-boson mass, and finally provide a window to heavy new gauge bosons W' and Z' in high-energy tails of differential distributions. It is the aim of this proposal to calculate the next-to-next-to-leading-order corrections of mixed QCD-EW type to these processes, i.e. the ones of the order O(alpha_s alpha), which represent the largest unknown type of radiative corrections in fixed-order of perturbation theory. Beyond their direct phenomenological importance in the description of W/Z production, the results of these calculations will impact predictions for other process classes as well. On the one hand, concepts, techniques, and partial results may be taken over to other reactions; one the other, a comparison of the new full results to existing approximations will help to tune or to systematically improve the approximative combination of QCD and electroweak radiative corrections. Technically and conceptually, the challenging calculations are at the forefront of perturbative calculations for particle reactions, but widely build on existing methods such as integration-by-parts and differential equations for the calculation of massive two-loop Feyman diagrams or antenna subtraction for the treatment of infrared singularities in real-emission corrections. Nevertheless, certain aspects require generalizations and further developments of existing concepts, such as the gauge-invariant treatment of intermediate W/Z resonances via the complex-mass scheme.

在欧洲核子研究中心的大型强子对撞机（LHC）中，W和Z玻色子的类似drell - yan的产生是最重要的粒子反应之一。作为探测器校准的标准烛光过程，它们提供了有效弱混合角和W-玻色子质量的高精度测量，并最终为差分分布高能尾的重新规范玻色子W‘和Z’提供了一个窗口。本文的目的是计算混合QCD-EW型对这些过程的次至次至前阶修正，即O阶（alpha_s alpha）的修正，这是摄动理论中定阶未知类型中最大的辐射修正。除了在W/Z生产描述中的直接现象学重要性之外，这些计算的结果也将影响对其他工艺类别的预测。一方面，概念、技术和部分结果可能被其他反应所接受；另一方面，将新的完整结果与现有近似值进行比较将有助于调整或系统地改进QCD和电弱辐射校正的近似值组合。从技术和概念上讲，具有挑战性的计算处于粒子反应微扰计算的前沿，但广泛建立在现有方法的基础上，如用于计算大量双环费曼图的分项积分和微分方程，或用于处理实际发射修正中的红外奇点的天线减法。然而，某些方面需要推广和进一步发展现有的概念，例如通过复杂质量方案处理中间W/Z共振的量规不变处理。