Precision Measurements of the Standard Model: PDFs, Pile-up, and Production of W+jets at 13 TeV with the ATLAS Detector

标准模型的精确测量：PDF、堆积以及使用 ATLAS 探测器在 13 TeV 下产生 W 射流

• 批准号: 2275170
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2275170
• 关键词: Precision; Measurements; Standard; Model; PDFs

Context:Precision Standard Model measurements will be performed, of vector boson (W/Z) + jet production, using the full Run 2 dataset from the Large Hadron Collider (LHC) at CERN. Such measurements are important to improve our understanding and modelling of these processes (important also in the context of new physics searches, where V+jet often constitute significant backgrounds). The student will in particular be responsible (at least in the first instance) for the W+jet measurement in the muon channel, which is currently uncovered, so there is substantial opportunity to make a leading contribution from the start. V+jets processes are also sensitive to proton structure, and the measurements performed will be used by the student (together with other data from HERA and the LHC) to determine improved proton parton distribution functions (PDFs). In addition, the student will spend some proportion of their time extending the state-of-the-art tools required for PDF determinations, in the context of the APPLfast project, which provides the technology to include new LHC cross section data in PDF determinations, and is used by all global PDF fitters world-wide. In addition, there will be significant opportunity for the student to expand into other areas in later years, including new physics searches, or Higgs measurements.Aims and objectives: Contribute to the operation of the ATLAS detector via shifts, and authorship qualification tasks within the JetEtmiss group, aiming to improve pileup mitigation techniques. Perform analysis using the full Run 2 ATLAS dataset, and investigate the impact of those measurements, and others, on constraining proton PDFs. Contribute to state-of-the-art tools, used world-wide for proton PDF determination. Publish results.Novelty of research and methodology:Measurements will be the most precise to date (using the full Run 2 dataset). We expect new analysis techniques to be developed, leading also to improved systematics. New Monte Carlo simulations, and state-of-the-art calculations will be used (including in the extraction of proton PDFs). Definition of new observables, never before measured, aimed at optimising sensitivity to QCD modelling, thus providing invaluable information for improved MC simulations and more precise determinations of backgrounds to new physics searches. Development of state-of-the-art software tools for proton PDF determination which will be used world-wide. Possible first measurements of rare Higgs decay channels.

背景：将使用欧洲核子研究中心大型强子对撞机（LHC）的完整运行2数据集进行矢量玻色子（W/Z）+喷流产生的精密标准模型测量。这种测量对于提高我们对这些过程的理解和建模非常重要（在新物理搜索的背景下也很重要，其中V+喷流通常构成重要的背景）。学生将特别负责（至少在第一个实例中）μ子通道中的W+喷流测量，目前尚未发现，因此从一开始就有很大的机会做出领先的贡献。V+喷流过程对质子结构也很敏感，学生将使用测量结果（以及HERA和LHC的其他数据）来确定改进的质子部分子分布函数（PDF）。此外，学生将花费一定比例的时间扩展PDF测定所需的最先进的工具，在APPLfast项目的背景下，该项目提供了将新的LHC横截面数据纳入PDF测定的技术，并被全球所有PDF拟合者使用。此外，学生将有很大的机会在以后的几年里扩展到其他领域，包括新的物理搜索，或希格斯测量。目的和目标：有助于ATLAS探测器的操作通过轮班，和JetEtmiss组内的作者资格任务，旨在提高堆积缓解技术。使用完整的运行2 ATLAS数据集执行分析，并研究这些测量和其他测量对约束质子PDF的影响。为世界范围内用于质子PDF测定的最先进的工具做出贡献。研究和方法的新奇：测量将是迄今为止最精确的（使用完整的运行2数据集）。我们期望开发新的分析技术，从而改进系统学。将使用新的蒙特卡罗模拟和最先进的计算（包括质子PDF的提取）。新的观测量的定义，从来没有测量，旨在优化灵敏度QCD建模，从而提供宝贵的信息，改进MC模拟和更精确的测定背景新的物理搜索。开发最先进的质子PDF测定软件工具，将在全球范围内使用。希格斯衰变通道的首次测量。