Beyond the Standard Model Scenarios: Dark Matter and Collider Signals

粒子物理标准模型是历史上最成功的科学理论之一。它可以用一些对称性原理和一些自然界的常量来解释广泛的亚原子现象。然而，有非常充分的理由相信，标准模型并不是关于物质基本结构问题的最终答案。一方面，模型中参数的整定存在理论上的顾虑。另一方面，中微子味道振荡和暗物质(对星系形成至关重要)的存在等实验证据在标准模型中仍然没有得到解释。人们普遍认为，解决这些难题需要存在新的粒子和/或新的相互作用。不幸的是，尽管有许多关于超越标准模型物理的预测，但没有确凿的证据证明存在新的粒子或相互作用。有两种可能的解释可以解释为什么到目前为止，新粒子可能逃脱了检测。首先，它们可能太重，在目前的实验中无法生产。到目前为止，我的大部分研究都集中在这个想法上，在我的新研究项目的一部分，我想重新审视这种可能性，并对涉及的假设进行仔细的研究(使用新开发的软件)，目的是扩大仍然可以用于新粒子和新相互作用的参数空间。第二种可能性是，新粒子被隐藏起来，因为它们与普通物质的耦合很弱。可能是它们的产生速度太小，或者它们形成了压缩频谱，也就是说，不容易产生观察到的信号。在这种情况下，最有希望的策略是进行更精确的测量，并增加实验中的事件数量(强度边界)以找到它们。我建议在大型强子对撞机上设计一些搜索，选择几乎不受背景干扰的可观测粒子，并补充到质子-质子碰撞中的搜索，以寻找重离子碰撞中的这些粒子。

The Standard Model of Particle Physics is one of the most successful scientific theories in history. It can explain a wide range of subatomic phenomena in terms of a few symmetry principles and a handful of constants of nature. There are however, very good reasons to believe that the Standard Model is not the final answer to questions about the fundamental structure of matter. On one hand, there are theoretical concerns about the tuning of the parameters in the model. On the other hand, experimental evidence such as the neutrino flavour oscillations and the existence of dark matter (crucial for the formation of galaxies) remains unexplained in the Standard Model. It is widely believed that the solution to these puzzles requires the existence of new particles and/or new interactions. Unfortunately, although many predictions of beyond the Standard Model physics are available, no conclusive proof of new particles or interactions exists. There are two possible explanations as to why new particles may have escaped detection so far. First, they could be too heavy to be produced in current experiments. Most of my research has been concentrated so far on this idea, and in part of my new research project, I would like to revisit this possibility, and perform a careful study of the assumptions involved (using newly developed software), with the purpose of widening the parameter space still available for new particles and new interactions. A second possibility is that the new particles are hidden, because they couple so feebly to ordinary matter. It may be that the rate at which they are produced is too small, or alternatively, that they form a compressed spectrum, that is, one which does not easily yield observed signals. In this case, the most promising strategy would be to make more precise measurements, and to increase the number of events in experiments (intensity frontier) to find them. I propose to devise some searches at the LHC by choosing observables with little interference from the background, and complimentary to searching in proton-proton collisions, to look for these particles in heavy ion collisions.