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LHC Physics with Electrons and Photons and the Achievement of the Full Performance Potential of the CMS Electromagnetic Calorimeter

LHC 电子和光子物理学以及 CMS 电磁热量计的全部性能潜力的实现

基本信息

批准号：
PP/D004519/1
负责人：
David Futyan
金额：
$ 57.14万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2006
资助国家：
英国
起止时间：
2006 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=PP%2FD004519%2F1
关键词：
LHC Physics Electrons Photons Achievement

项目摘要

The Large Hadron Collider (LHC), located at CERN near Geneva, Switzerland, will be the world's largest particle accelerator. The machine, which is due to begin operation in summer 2007 will collide high energy protons travelling in opposite directions around a 27 km ring. The Compact Muon Solenoid (CMS) is a general purpose detector and is one of four large particle detectors to be positioned at collision points around the ring. One of the key components of the CMS detector is the Electromagnetic Calorimeter (ECAL). This is composed of over 75000 lead tungstate crystals and is designed to accurately measure the positions and energies of electrons and photons. The proposed project is to ensure that the design performance potential of the CMS ECAL is fully exploited, and to play a decisive and leading role in the discovery of new physics at the LHC, focusing on the use of the electromagnetic calorimeter. One of the primary objectives of the LHC experimental program is to elucidate the origin of mass, in particular through the discovery the Higgs boson, an elementary particle predicted by the Standard Model of particle physics. The particle is unstable and when produced in proton-proton collisions at the LHC will immediately decay into less massive particles. It is the stable particles in the final state, such as electrons, muons or photons, which will be observed by the detector. The mass of the parent Higgs boson can be reconstructed from the combined momenta of the final state particles. The decay channels of the Higgs boson which yield the highest sensitivity for discovery at the LHC all have final states which may contain electrons or photons. The achievement of the full design performance of the CMS ECAL is therefore of crucial importance to the discovery of the Higgs boson. My primary task over the last two years has been to develop the first complete physics analysis with full simulation of the CMS detector for one of the most important channels for the discovery of the Higgs boson. One of the pre-requisites for any LHC physics analysis is accurate reconstruction of final state particles. The challenge for the CMS ECAL concerns the precise reconstruction of the positions and energies of electrons and photons and their accurate and efficient identification and selection. I am now the leading expert in these areas, and my objective for the first one to two years of the project will be to continue to focus on the development of robust reconstruction software in preparation for the start of the experiment. In the second or third year of the project I aim to take up a leading role, concerning the ECAL, in the commissioning of the CMS detector. The major task of performing the relative calibration of the 75000 ECAL crystals would be my next area of focus during early data taking. My next objective will be to study key Standard Model signals, and in particular, electrons produced from the decay of the W boson. As well as being the main channel used to calibrate the ECAL, this channel provides a detailed probe of the detector performance, and will be a key to understanding many new physics signals. The accurate and efficient reconstruction of electrons and photons in a precisely calibrated ECAL will provide the maximum possible potential for the discovery of new physics which may become accessible through the LHC. As the data taken by CMS accumulates, my experience from my current Higgs analysis and from previous analyses will place me in a strong position to act as a key player in the discovery and study of new physics signals using CMS data. I aim to take the lead in a number of physics analyses, extending my expertise to other Higgs boson decay channels. Finally, I will be able to use my knowledge and experience from the OPAL experiment to develop techniques to combine results from the different search channels to ensure the timely discovery of the Higgs boson and other new physics.

大型强子对撞机（LHC）位于瑞士日内瓦附近的欧洲核子研究中心，将是世界上最大的粒子加速器。这台将于2007年夏季开始运行的机器将使围绕27公里长的环向相反方向运动的高能质子发生碰撞。紧凑型μ子螺线管（CMS）是一个通用探测器，是四个大型粒子探测器之一，将被定位在环周围的碰撞点。CMS探测器的关键部件之一是电磁量热计（ECAL）。它由超过75000个钨酸铅晶体组成，旨在精确测量电子和光子的位置和能量。该项目旨在确保CMS ECAL的设计性能潜力得到充分利用，并在LHC新物理的发现中发挥决定性和主导作用，重点是电磁量能器的使用。大型强子对撞机实验计划的主要目标之一是阐明质量的起源，特别是通过发现希格斯玻色子，粒子物理学标准模型预测的基本粒子。这种粒子是不稳定的，当在LHC的质子-质子碰撞中产生时，会立即衰变成质量较小的粒子。它是处于终态的稳定粒子，如电子、μ子或光子，将被探测器观测到。母希格斯玻色子的质量可以从末态粒子的动量重建。希格斯玻色子的衰变通道在大型强子对撞机上产生最高的发现灵敏度，它们都有可能包含电子或光子的最终状态。因此，CMS ECAL的完整设计性能的实现对于希格斯玻色子的发现至关重要。在过去的两年里，我的主要任务是开发第一个完整的物理分析，并对CMS探测器进行全面模拟，这是发现希格斯玻色子的最重要渠道之一。任何LHC物理分析的前提之一是精确重建末态粒子。CMS ECAL的挑战涉及电子和光子的位置和能量的精确重建以及它们的准确和有效的识别和选择。我现在是这些领域的主要专家，我在项目最初一到两年的目标是继续专注于开发强大的重建软件，为实验的开始做准备。在项目的第二年或第三年，我的目标是在CMS探测器的调试中发挥主导作用，涉及ECAL。对75000个ECAL晶体进行相对校准的主要任务将是我在早期数据采集期间的下一个重点领域。我的下一个目标是研究标准模型的关键信号，特别是从W玻色子衰变中产生的电子。除了作为用于校准ECAL的主通道外，该通道还提供了探测器性能的详细探测，并且将成为理解许多新物理信号的关键。在精确校准的ECAL中准确和有效地重建电子和光子将为发现新物理提供最大可能的潜力，这些物理可能通过LHC获得。随着CMS收集的数据的积累，我目前的希格斯分析和以前的分析经验将使我处于一个有利的位置，在使用CMS数据发现和研究新的物理信号方面发挥关键作用。我的目标是在一些物理分析中发挥带头作用，将我的专业知识扩展到其他希格斯玻色子衰变通道。最后，我将能够利用我在OPAL实验中的知识和经验，开发技术，将不同搜索渠道的结果联合收割机结合起来，以确保及时发现希格斯玻色子和其他新物理。