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arXiv 1611.04450hep-ph
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SUSY模型和在ILC压缩谱区的暗物质测定

SUSY model and dark matter determination in the compressed-spectrum region at the ILC

Mikael Berggren

摘要:

超对称性理论可以完全解释宇宙中观测到的暗物质密度,这是一个很有吸引力的可能性。目前的实验知识表明,这种可能性强烈倾向于共同湮灭的情况。在这种情况下,次轻的超对称粒子(NLSP)和最轻的超对称粒子(LSP)之间的质量差非常小,这确保了湮灭截面足以预测暗物质的丰度不会太大。然而,小的质量差也意味着在强子对撞机上观察超对称性变得困难,在那里观察取决于丢失横向能量的信号:如果NLSP到LSP的质量差很小,只有很少的能量被不可见的LSP带走。即使其他几个超对称粒子在运动学范围内,这也是正确的,因为这些状态在很大程度上会通过级联衰减,以NLSP到LSP衰减结束。轻子对撞机没有这个问题。这种机器的清洁环境和已知的初始状态确保了即使质量差非常小,只要质心能量足够高,也可以检测到超对称性。我们提出的展望,超对称性的观测和精度表征的小质量差异在ILC,ILD探测器的概念的详细模拟的基础上。由此产生的可能性预测的暗物质遗迹密度进行评估,并从普朗克任务获得的精度进行比较。以一个具体的模型为例,我们还讨论了ILC和HL-LHC结果相结合的协同作用。

英文摘要:

It is an appealing possibility that the observed dark matter density in the universe can be fully explained by SUSY. The current experimental knowledge indicates that this possibility strongly favors a co-annihilation scenario. In such scenarios, the mass difference between the next-to-lightest SUSY particle (the NLSP) and the lightest one (the LSP) is quite small, which assures that the annihilation cross-section is sufficient not to predict a too large abundance of dark matter. However, the small mass difference also means that observing SUSY becomes hard at hadron colliders, where the observation hinges on the tell-tale signature of missing transverse energy: if the mass difference NLSP-to-LSP is small, only little energy is carried away by the invisible LSP. This is also true even if several other SUSY particles are within the kinematic reach, since these states would to a large extent decay via cascades ending with an NLSP to LSP decay. A lepton collider does not have this problem. The clean environment and known initial state at such machines assures that SUSY can be detected even if the mass difference is very small, provided the center-of-mass energy is sufficiently high. We present prospects for observation and precision characterization of SUSY with small mass differences at the ILC, based on detailed simulations of the ILD detector concept. The resulting possibility to predict the dark matter relic density is evaluated and compared to the precision obtained from the Planck mission. Taking a specific model as an example, we also discuss the synergies from combining ILC and HL-LHC results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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