Bridging grant application for ATLAS-Canada: Electroweak multi-boson interactions at the Large Hadron Collider

粒子物理学的标准模型（SM）提供了目前对基本粒子及其相互作用的最佳描述。然而，有许多现象不在SM的范围之内。粒子相互作用由四种力介导：强、弱、电磁力和引力。强、弱和电磁力是由所谓的规范玻色子介导的：分别是胶子、W和Z玻色子以及光子。在欧洲核子研究中心（CERN）的大型强子对撞机（LHC）中探测到的高能质子-质子碰撞中，弱力和电磁力统一为电弱力。大型强子对撞机使我们能够以前所未有的精度在最高的能量尺度上探测电弱相互作用的复杂细节。此外，为了解释暗物质和宇宙的物质-反物质不对称，需要对SM进行扩展，这与SM电弱相互作用的修正密切相关，而大型强子对撞机为探索这些相互作用提供了最丰富的环境。这笔拨款将使我能够在大型强子对撞机领导一个新的研究项目，以回答有关电弱相互作用的基本问题。在pp碰撞的电弱相互作用中产生多规范玻色子是非常罕见的，但SM精确地预测了这一点。因此，任何现有的多玻色子测量目前都受到实验精度的限制，我们对这些过程的理解也明显有限。因此，通过对这些过程的研究，有可能揭示与这些粒子耦合的新物理现象。在大型强子对撞机上无法直接搜索到的TeV能量尺度的新粒子，可以改变多玻色子过程的速率或运动学。我将带头进行对两个W玻色子和两个光子之间的相互作用敏感的三种测量进行组合有效场论拟合的努力。这种组合将为任何尚未发现的粒子提供最佳灵敏度，并显示这些粒子可能隐藏在我们搜索之外的任何区域。确定这些未覆盖的区域将有助于告知我们未来的测量，并为Run 3做准备。此外，我将为Run 3及以后的ATLAS Trigger软件做出贡献。自2017年1月以来，我一直在研究触发器，并为增加我们在Run 2中记录的信号拓扑的宽度做出了重大贡献。在Run 3中，高级触发器软件将多线程运行，完成和调试软件需要大量的工作。我将致力于设计和优化Run 3的整体事件选择，以确保我们能够保持Run 1和Run 2中ATLAS记录的整体高质量数据。

The Standard Model (SM) of particle physics provides the current best description of elementary particles and their interactions. However, there are many phenomena that are outside the scope of the SM. Particle interactions are mediated by four forces: strong, weak, electromagnetic, and gravitational. The strong, weak, and electromagnetic forces are mediated by so-called gauge bosons: gluons, W and Z bosons, and photons, respectively. At the high energies probed in proton-proton collisions at the Large Hadron Collider (LHC) at CERN, the weak and electromagnetic forces are unified into the electroweak force. The LHC allows us to probe the intricate details of electroweak interactions at the highest-ever energy scales with unprecedented precision. Furthermore, the required extensions to the SM to explain dark matter and the matter-antimatter asymmetry of the universe are intimately tied to modifications of SM electroweak interactions, and the LHC provides the richest environment in which to probe these interactions. This grant will enable me to lead a new research programme at the LHC to answer fundamental questions about electroweak interactions. The production of multiple gauge bosons in electroweak interactions in pp collisions is extremely rare but precisely predicted by the SM. As such, any existing multi-boson measurements are currently limited in experimental precision, and our understanding of these processes is markedly limited. It is therefore possible that new physics phenomena that couple to these particles could be revealed through the study of such processes. New particles at the TeV energy scale, out of reach from direct searches at the LHC, can alter the rate or kinematics of multi-boson processes. I will spearhead the effort to perform a combined effective field theory fit of the three measurements that are sensitive to the interaction between two W bosons and two photons. This combination will provide optimal sensitivity to any as-of-yet undiscovered particles, as well as showing any areas where such particles could be hidden from our searches. Identifying these uncovered areas will help inform our future measurements - and preparations for Run 3. Additionally, I will contribute to the ATLAS Trigger software for Run 3 and beyond. I have worked on the trigger since January 2017, and have made significant contributions towards increasing the breadth of signal topologies we recorded in Run 2. In Run 3, the high-level trigger software will run multithreaded, and a significant amount of work is necessary to complete and commission the software. I will work on designing and optimizing the overall event selection for Run 3 to ensure we can maintain the overall high quality of data ATLAS recorded in Runs 1 and 2.