在 LHC 上寻找超粒子的研究

Both the fine-tuning problem in the Standard Model (SM) and the experimental data at the Large Hadron Collider (LHC) indicate the existence of new physics beyond the SM. As one of the best candidates, the low energy supersymmetric models have been extensively investigated, and among them, the Next to Minimal Supersymmetric Standard Model (NMSSM) has attracted much attention because it can give the mass near 125 GeV of SM-like Higgs boson naturally, meanwhile could satisfy the constraints of LHC searches for sparticles, the measured Dark Matter relic density and results from direct detections of Dark Matter. Therefore, we mainly study the phenomenology of NMSSM based on LHC searches for sparticles.. Following the theoretical progress and experimental development, with the help of scanning packages and tools of Monte Carlo simulation in particle physics, we study the phenomenology of the NMSSM at the LHC and characters of parameter space in the NMSSM satisfying constraints from the LHC searches. Besides we also study the further detection of our scenario by the high energy or high luminosity LHC. Moreover, we study theoretical issues such as the fine-tuning problem to further improve our understanding of the NMSSM. Our study will enrich the phenomenology study of the NMSSM and provide guideline for experimentalists in new physics search.

标准模型中精细调节问题和 LHC 上的实验数据均表明有超出标准模型的新物理，低能超对称模型作为新物理的候选者被广泛研究，其中次最小超对称模型（NMSSM）由于其能自然地预言 125 GeV 类标准模型 Higgs 粒子，同时容易满足 LHC 寻找超粒子、暗物质残留密度、暗物质直接探测等实验限制而备受关注。因此本项目主要在 NMSSM 中开展 LHC 寻找超粒子研究。. 本项目将密切跟踪 NMSSM 的理论动态和 LHC 实验进展，利用国际上先进的扫描程序包和粒子物理蒙特卡洛模拟工具，探讨 LHC 寻找超粒子结果，明确实验倾向的参数空间并研究它在 LHC 上的现象；讨论未来高能量、高亮度 LHC 对超粒子的探测能力；通过对精细调节问题等的研究，加深对 NMSSM 性质的理解。本项目一方面丰富 NMSSM 唯象学，另一方面为对撞机实验探测 NMSSM 提供理论指导。

我们考虑了目前最新的暗物质直接和间接探测实验限制和LHC实验限制，重新分析了NMSSM模型中存活参数点的特征，研究了模型的自然性问题，并且计算了可以由实验验证的散射截面。.我们研究了在满足目前暗物质和Collider实验限制下，NMSSM模型进一步满足Mass-degenerate 125 GeV 双希格斯粒子的存活参数点，并且指出在Mass-degenerate 125 GeV 双希格斯粒子在LHC上的信号特点。.我们还在NMSSM模型中解释了Galactic Center gamma-ray Excess (GCE)，并且同时考虑了PandaX-II的实验限制。.这些都是粒子物理和新物理研究的重要成果。