Precision Cross Section Measurements and Searches for New Physics with ATLAS

使用 ATLAS 进行精确横截面测量和新物理探索

• 批准号: PP/E006442/1
• 负责人: Jan Kretzschmar
• 金额: $ 27.01万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=PP%2FE006442%2F1
• 关键词: Precision; Cross; Section; Measurements; Searches

The nature of the fundamental constituents of matter and their interactions have inspired mankind at least since the days, when the idea of indivisible elementary particles was formulated by ancient Greek philosophers. Today we stand at a point, where the best known theory - the Standard Model (SM) - has been tested over the last 30 years with a very high precision in many experiments at large particle accelerators. Even though the SM has been able to describe all discovered effects, many miracles remain to be solved. For example astrophysical observations show, that the matter we know and have studied up to now makes up only 1/20th of the matter content of the universe. The Large Hadron Collider (LHC) is the highest energy particle accelerator ever build. It collides protons at energies at least 7 times higher than in every other facility. The complex ATLAS experiment was designed to register the outcome of these violent collisions. With the help of LHC and ATLAS we may be able to solve some of the open questions within a few years. One solution may be so called Super Symmetric theories, where every fundamental particle we know today is assigned a partner. If these new particles exists, they should be discovered at the LHC and their properties will be studied. The first task will be to understand the properties of the ATLAS experiment, one of the most complex technical devices ever build. It is approximately 26 m long, 20 m high, and weighs 7000 tons. Still, some of the inner components, the silicon track detectors, have to be positioned with an accuracy of a few 1/1000 of a millimetre. Together with the experts in Liverpool, who build a part of these detectors, I will determine corrections to achieve the best possible measuring accuracy. The next task will be accurate measurements of the production of known Standard Model particles, so called W bosons. This measurement will show how well we understand the experimental apparatus, the Standard Model, and the composition of the proton from elementary particles. Using all the information we have today, we are able to predict the rate with which the W bosons are produced, so we can compare the measurements to our expectation. Finally, I will look for the particles predicted by theories that go beyond the Standard Model. If any of these new particles are produced, they will decay rapidly to other known particles which can be registered by ATLAS. I propose to concentrate my search on decays, where an electron and its antimatter partner, the positron, are produced together with other highly energetic objects (so called jets) and the candidate particle for the dark matter. Theorists tell us, that this kind of events will happen for many different types of new models, but the Standard Model predicts very low rates. The decay products will carry enough information of their parents, so the properties of the fundamental theory can be determined. I am looking forward to contributing to this exciting scientific program, which may significantly enhance our understanding about the basic building blocks and laws of nature.

物质的基本成分的性质及其相互作用至少从古希腊哲学家提出不可分割的基本粒子的概念以来就一直激励着人类。今天，我们站在一个点上，最著名的理论-标准模型（SM）-在过去的30年里已经在大型粒子加速器的许多实验中以非常高的精度进行了测试。即使SM已经能够描述所有发现的效果，许多奇迹仍然有待解决。例如，天体物理学的观测表明，我们所知道的和迄今为止所研究的物质只占宇宙物质含量的1/20。大型强子对撞机（LHC）是有史以来建造的能量最高的粒子加速器。它碰撞质子的能量至少是其他设施的7倍。复杂的ATLAS实验旨在记录这些剧烈碰撞的结果。在LHC和ATLAS的帮助下，我们可能能够在几年内解决一些悬而未决的问题。一个解决方案可能是所谓的超对称理论，其中我们今天所知道的每个基本粒子都被分配了一个伙伴。如果这些新粒子存在，它们应该在LHC中被发现，并将被研究它们的性质。第一项任务将是了解ATLAS实验的特性，这是有史以来最复杂的技术设备之一。它长约26米，高约20米，重约7000吨。尽管如此，一些内部组件，硅轨道探测器，必须以千分之几毫米的精度定位。我将与利物浦的专家一起确定修正，以达到最佳的测量精度。下一个任务将是精确测量已知标准模型粒子的产生，即所谓的W玻色子。这一测量将显示我们对实验装置、标准模型以及质子与基本粒子的构成的理解程度。利用我们今天所拥有的所有信息，我们能够预测W玻色子产生的速率，因此我们可以将测量结果与我们的预期进行比较。最后，我将寻找超越标准模型的理论所预测的粒子。如果这些新粒子中的任何一个产生，它们将迅速衰变为其他已知的粒子，这些粒子可以被ATLAS记录下来。我建议把我的研究集中在衰变上，在衰变中，电子和它的反物质伙伴，正电子，与其他高能物体（所谓的喷流）和暗物质的候选粒子一起产生。理论家告诉我们，这种事件会发生在许多不同类型的新模型中，但标准模型预测的概率非常低。衰变产物将携带它们的母体的足够信息，因此可以确定基本理论的性质。我期待着为这个令人兴奋的科学计划做出贡献，这可能会大大提高我们对自然的基本组成部分和规律的理解。

项目成果

Measurement of the W ? l? and Z/? * ? ll production cross sections in proton-proton collisions at $ \sqrt {s} = 7\;{\text{TeV}} $ with the ATLAS detector

W 的测量？

• DOI: 10.1007/jhep12(2010)060
• 发表时间: 2010
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: Aad G

Measurement of the inclusive ep scattering cross section at low Q 2 and x at HERA

• DOI: 10.1140/epjc/s10052-009-1128-6
• 发表时间: 2009-10-01
• 期刊: EUROPEAN PHYSICAL JOURNAL C
• 影响因子: 4.4
• 作者: Aaron, F. D.;Alexa, C.;Zomer, F.
• 通讯作者: Zomer, F.

A precision measurement of the inclusive ep scattering cross section at HERA

• DOI: 10.1140/epjc/s10052-009-1169-x
• 发表时间: 2009-12-01
• 期刊: EUROPEAN PHYSICAL JOURNAL C
• 影响因子: 4.4
• 作者: Aaron, F. D.;Alexa, C.;Zus, R.
• 通讯作者: Zus, R.

Electron performance measurements with the ATLAS detector using the 2010 LHC proton-proton collision data

• DOI: 10.1140/epjc/s10052-012-1909-1
• 发表时间: 2012-03-01
• 期刊: EUROPEAN PHYSICAL JOURNAL C
• 影响因子: 4.4
• 作者: Aad, G.;Abbott, B.;Zwalinski, L.
• 通讯作者: Zwalinski, L.