Non-standard signatures of Composite Higgs models and their impact for searches at present and future colliders

2012年在大型强子对撞机上发现希格斯玻色子无疑是数十年基础物理研究的顶峰，也是粒子物理标准模型的成功故事。然而，它不能被认为是一个成功的完成，因为在标准模型中，布鲁特-恩格勒-希格斯机制仅仅是对电弱对称性破缺的描述，而没有对其动力学起源的任何理解。在125 GeV的标量共振的发现已经实现了这个问题，通常被称为自然性问题。此外，标准模型之外的新物理学的长期证据仍在等待有效的粒子物理学解释：中微子质量，暗物质和宇宙的重子不对称性。此外，是什么导致了夸克和轻子质量谱的结构仍然是一个谜。复合希格斯玻色子模型提供了希格斯玻色子作为伪南武-戈德斯通玻色子的动力学解释。顶部质量的巨大性可以通过与所谓的超重子的混合来解释。LHC合作组以最小复合Higgs模型为指导，建立了这些超重子和其他束缚态的严格界限。虽然最小模型对于初步了解潜在签名非常有用，但更现实的模型中的情况要复杂得多。例如，它们不仅含有附加的电弱赝南武-戈德斯通玻色子，而且还含有在强相互作用下带电的玻色子。它们的存在显著地改变了超重子和其他束缚态的衰变模式。此外，相对于最小模型，再论模型经常预测强子对撞机上额外的超重子，其产生截面明显更大。这对对撞机搜索的签名有着深远的影响，比如LHC。在这个项目中，我们将详细调查这一点：首先，我们将探索在现有的LHC数据中是否有这种改变的签名的痕迹。其次，我们将工作的影响，即将到来的大型强子对撞机运行和一个前瞻性的100 TeV质子质子对撞机。

The discovery of the Higgs boson at the LHC in 2012 has certainly been the crowning of many decades of research in fundamental physics and a success story for the Standard Model of particle physics. However, it cannot be considered a successful completion because the Brout-Englert-Higgs mechanism appears in the Standard Model as a mere description of the electroweak symmetry breaking, without any understanding of its dynamical origin. The discovery of a scalar resonance at 125 GeV has materialised this problem, often referred to as the naturalness problem. Furthermore, long standing evidences of new physics beyond the Standard Model are still waiting for a valid particle physics explanation: neutrino masses, dark matter and the baryon asymmetry of the Universe. In addition there remains the riddle what causes the structures of the observered quark and lepton mass spectra. Composite Higgs models offer a dynamical explanation of the Higgs boson as a pseudo Nambu-Goldstone-boson. The largeness of the top-mass is explained via mixing with so-called hyperbaryons. The LHC collaborations have established servere bounds on these hyperbaryons and other bound states taking the minimal composite Higgs model as guideline. While the minimal model is quite useful to get a first idea on potential signatures, the situation in more realistic models is much more complex. For example, they contain not only additional electroweak pseudo Nambu-Goldstone-bosons but also ones charged under the strong interaction. Their existence change significantly the decay pattern of the hyperbaryons and other bound states. Moreover, relistic models often predict additional hyperbaryons with a significantly larger production cross section at hadron colliders compared to the ones of the minimal model. This has profound implications on the signatures for collider searches such as the ones at the LHC. In this project we will investigate this in detail: firstly we will explore if there are traces of such altered signatures in the existing LHC data. Secondly we will work out the implications for the reach of upcoming LHC runs and a prospective 100 TeV proton proton collider.