Bridging grant application for ATLAS-Canada; Prompt and Long-Lived Particles - Searching for new physics at the Energy Frontier

拟议中的研究计划将作为一个桥梁，我在欧洲核子研究中心的大型强子对撞机（LHC）的ATLAS实验参与。作为加拿大西蒙弗雷泽大学的一名新教师，这个最初的NSERC发现补助金将资助我的新研究计划的启动，然后将继续通过在2021年比赛期间更新NSERC ATLAS-加拿大项目补助金提供资金。此申请描述了我将在今年（要求一年）开始的计划，以及我希望在未来五年内开展的计划。这些资金将使我能够建立一个杰出的研究计划，在下一个LHC数据采集期（从2021年开始）之前解决迫在眉睫的挑战，并加强加拿大在世界上最受推崇的科学努力之一中的作用。 标准模型就像牛顿物理学一样--一个成功的故事：它描述了宇宙中所有可见的物质和所有的力（除了引力），它描述了基本粒子如何获得质量（希格斯机制）。50多年来，所有预测都已通过实验验证，具有极高的精度。这个谜题的最后一块是在2012年添加的：ATLAS和CMS实验发现了希格斯玻色子。 现在，我们测试这个标准模型的极限，以便找到一个不一致的地方，并确定关于超越标准模型（BSM）的物理学的线索。揭示这些线索的一个有希望的方法是推进到高能量，在那里我们期待一个新的理论来揭示自己。LHC是有史以来最强大的粒子加速器，为探索这一高能前沿提供了独特的机会。我在这里的主要目标是使用ATLAS探测器来寻找长寿新粒子（LLP）签名的迹象，以揭示宇宙中最大的谜团：为什么在早期宇宙中物质战胜反物质以及暗物质是什么。寻找这些粒子是非常具有挑战性的，因为它们往往不与其他物质相互作用，使它们难以检测。 在大型强子对撞机上对新物理的绝大多数研究都是在假设新粒子迅速衰变的情况下进行的，即，非常接近质子-质子相互作用点。然而，SM中的粒子的寿命（）跨越了巨大的数量级范围，从Z玻色子（10 - 25秒）到质子（> 1034 y）和电子（稳定）。类似地，BSM模型通常预测具有各种寿命的新粒子。BSM LLP在检测器内的产生点和衰变点之间可能具有宏观的、可检测的位移。他们不寻常的签名为在下一个数据采集期间在粒子对撞机上发现新物理提供了极好的前景。同时，标准重建算法可能会拒绝包含LLP的事件或对象，因为它们的不寻常性质，并且需要专门的搜索来发现LLP信号。

The proposed research program will act as a bridge to my participation in the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. As a new faculty member in Canada at Simon Fraser University, this initial NSERC Discovery Grant will fund the initiation of my new research program, which will then continue with funding made available by a renewal of the NSERC ATLAS-Canada project grant during the 2021 competition. This application describes the program that I will initiate during this year (request for one year) and that I expect to carry out within the next five years. These funds will allow me to establish an outstanding research program, address imminent challenges ahead of the next LHC data taking period (starting 2021), and enhance Canada's role in one of the world's most highly regarded scientific endeavors. The Standard Model is like Newtonian physics - a success story: it describes all visible matter in the Universe and all forces (with the exception of gravity), and it describes how elementary particles acquire a mass (Higgs mechanism). All predictions have been verified by experiment with excellent precision for more than 50 years. The last piece to this puzzle was added in 2012: the Higgs boson discovery by the ATLAS and CMS experiments. Now we test the limits of this SM in order to find an inconsistency and ascertain clues about physics Beyond the Standard Model (BSM). One promising way to reveal such clues is to push to high energies, where we expect a new theory to reveal itself. The LHC is the most powerful particle accelerator ever built and provides a unique opportunity to explore this high-energy frontier. My primary objective here will be to use the ATLAS detector to search for signs of long-lived new particle (LLP) signatures in order to shed light on the universe's biggest remaining mysteries: why matter prevailed over antimatter in the early universe and what dark matter is. Searching for these particles is highly challenging, as they tend not to interact with other matter, making them elusive to detection. The overwhelming majority of searches for new physics at the LHC have been performed under the assumption that the new particles decay promptly, i.e., very close to the proton-proton interaction point. However, particles in the SM have lifetimes () spanning an enormous range of magnitude, from the Z boson (10-25s) through to the proton (>1034y) and electron (stable). Similarly, BSM models typically predict new particles with a variety of lifetimes. BSM LLPs may have macroscopic, detectable displacements between their production and decay points within the detector. Their unusual signatures offer excellent prospects for the discovery of new physics at particle colliders during the next data-taking period. At the same time, standard reconstruction algorithms may reject events or objects containing LLPs precisely because of their unusual nature, and dedicated searches are needed to uncover LLP signals.