Experimental Particle Physics at the University of Edinburgh

爱丁堡实验粒子物理小组目前正在进行三个不同的实验，我们也在进行几个未来的项目。在大型强子对撞机（LHC）上的ATLAS实验：ATLAS是两个能够研究各种各样的粒子的探测器之一，这些粒子是由有史以来最高能量的质子碰撞产生的，它解决了一些基本问题。最著名的是质量的起源。作为我们理解粒子相互作用基础的美丽的对称性本质上要求所有粒子都是无质量的。这是不可能的，而提出的优雅解决方案现在被称为希格斯机制。希格斯玻色子的发现证实了这一点，现在我们必须非常详细地测量它的性质。ATLAS的另一个领域是寻找新的重粒子，如新的重希格斯粒子或超对称粒子，这些粒子是在试图解决标准模型（SM）缺陷的模型中预测的，例如为什么会有暗物质。LHC的LHCb实验。在20世纪60年代之前，人们一直认为物质和反物质的行为是相同的。然而，人们发现这种对称性被破坏了，物质的行为方式与反物质不同。这体现在CP破坏现象中，对于理解早期宇宙至关重要。大爆炸后不久，物质和反物质的数量相等。在膨胀和冷却过程中，物质和反物质会湮灭成光子，留下一个充满辐射的宇宙，但没有恒星和星系。1967年，萨卡洛夫证明，如果满足包括CP破坏在内的三个条件，那么物质与反物质之间的微小不平衡就有可能产生，这足以解释宇宙的存在。LHC B测量具有至少一个B或反B夸克的粒子和反粒子的行为差异（CP破坏），并搜索这些粒子的非常罕见的衰变，这可能受到未观测到的重粒子的影响。LUX-ZEPLIN实验，这是世界上最灵敏的寻找暗物质的仪器。众所周知，宇宙的27%是由暗物质组成的，暗物质是某种形式的物质，它们不会以产生辐射或其他容易观察到的特征的方式相互作用。有许多理论上的候选者和解决这个谜必须包括我们自己的银河系暗物质的直接检测。我们领导了合作项目，以探测包括轴子和暗声子在内的特别有意义的可能性。我们还在努力设计、开发和建造2020年左右在LHC上升级的探测器。光束的强度将增加，探测器记录的数据速率将增加几个数量级。这需要建造新的探测器来精确测量长寿命粒子的轨迹，测量切伦科夫光子以确定它们的速度，更快，更强大的模拟，以及处理大量数据速率的新方法。我们现在已经完成了LUX-ZEPLIN项目的建设，预计将在未来十年内主导对暗物质的直接搜索。我们致力于10吨液态氙的模拟、控制系统和分析。我们在即将建造的DUNE和Hyper-K实验中发展了中微子物理学活动。自然界最有趣的事实之一是，中微子只有三种，直到最近才被认为是无质量的。精确测量中微子的“混合”和寻找中微子的CP破坏是很重要的。我们还加入了MicroBooNE和SBND实验，这些实验将寻找新的、无菌的中微子，它们只通过引力相互作用，而不与SM的任何基本相互作用相互作用。

The Edinburgh Experimental Particle Physics group is currently working in three different running experiments and we are also working on several future projects.The ATLAS experiment at the Large Hadron Collider (LHC): ATLAS is one of two detectors able to study a wide variety of particles created from the collision of protons at the highest energies ever created, and it addresses fundamental questions. The most well known is that of the origin of mass. The beautiful symmetry which underlies our understanding of particle interactions inherently demands that all particles are massless. This cannot be the case, and the elegant solution put forward is now known as the Higgs mechanism. The discovery of the Higgs boson has verified this, and now we must measure its properties in great detail. Another area addressed by ATLAS is the search for new heavy particles such as new heavy Higgs like particles or supersymmetric particles, which are predicted in models trying to address shortcomings of the Standard Model (SM), such as why there is dark matter.The LHCb experiment at the LHC. Prior to the 1960s, it had been thought that matter and anti-matter would behave in the same way. However, it was discovered that this symmetry was violated, and that matter does not behave in an identical way to anti-matter. This is embodied in the phenomenon of CP violation and is essential to the understanding of the early universe. Shortly after the big bang there were equal amounts of matter and anti-matter. During expansion and cooling, matter and anti-matter would have annihilated into photons to leave a universe full of radiation, but no stars and galaxies. It was shown in 1967 by Sakarov that if three conditions, including CP violation, were met, then it would be possible for a small imbalance of matter over anti-matter to accrue, which would be sufficient to explain the existence of the universe. LHCb measures differences (CP violation) in behaviour of particles and antiparticle with at least one b or anti-b quark and searches for very rare decays of these particles, which could be affected by heavy unobserved particles. The LUX-ZEPLIN experiment, which is the world's most sensitive apparatus searching for dark matter. It is well known that some 27% of the Universe is comprised of Dark Matter - that is matter of some form which does not interact in a way that produces radiation, or other easy to observe signatures. There are many theoretical candidates and resolution of this mystery must include the direct detection of our own galactic dark matter. We lead the collaboration's efforts to detect particularly well-motivated possibilities including axions and dark phonons.We are also working hard on the design, development and construction of the upgraded detectors at the LHC for around 2020. The intensity of the beams will be increased and the data rates recorded by the detectors will increase by orders of magnitude. This requires building new detectors for precisely measuring trajectories of longlived particles, for measuring Cherenkov photons to determine their speed, and faster and more powerful simulation, and new ways to handle the massive data rates. We have now completed the construction of the LUX-ZEPLIN project, expected to dominate direct searches for dark matter in the next decade. We work on simulations, control systems for the 10 tonnes of liquid xenon, and analysis.We have grown our neutrino physics activities in the DUNE and Hyper-K experiments to be constructed. One of the most interesting facts of nature is that there are only three species of neutrinos, which until recently were thought to be massless. It is important to measure precisely the "mixing" between the species and to search for CP violation in neutrinos. We have also joined the MicroBooNE and SBND experiments, which will search for new, sterile, neutrinos which interact only via gravity but not with any of the fundamental interactions of the SM.