New light physics beyond the Standard Model

超越标准模型的新光物理

• 批准号: 2889508
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2889508
• 关键词: New; light; physics; beyond; Standard

The project will involve studying the properties of possible new light particles beyond the Standard Model of particle physics and their astrophysical and cosmological signatures and constraints, with the aim to make predictions relevant to high energy theories, such as string theory, as well as upcoming experimental searches. The initial aim will be to reliably calculate the constraints on Kaluza Klein gravitons coming from the observation of a neutrino burst from supernoava 1987a, correcting previous calculations by taking into account plasma mixing effects (which might change the resulting limits on the coupling constants of such gravitons to visible sector matter by orders of magnitude). Such particles have been (controversially) predicted by string theory models as an inevitable consequence of the cosmological constant, and a strengthened constraint could rule out this scenario or open an avenue to a discovery. Plasma mixing effects have previously been considered for scalars (spin 0) and vectors (spin 1) but this would be the first ever computation for a spin 2 particle. The methodology will involve using techniques from finite temperature field theory to account for the in-medium effects on the production rate, and in particular the possibility of resonant production building on the previous work for the lower spin case. Depending on the results, it might also be interesting to investigate the impact of such finite temperature effects on the cosmological history of Kaluza Klein gravitons; since the Universe was extremely hot at early times such effects could again lead to dramatic changes compared to the previous prediction. This will enable a precise prediction of the Dark Matter relic abundance of such particles (which has previously been only estimated) and it might lead to predictions that can be feed into an experimental search programme. Subsequently, the scope will be widened to consider the constraints on other classes of new particles including axions, which are especially well motivated, as well as possible new light scalars that might play a role in sourcing Dark Energy. Again in this case, finite temperature and density effects have not been consistently accounted for. The overall impact of the project will be 1. On the immediate field of researchers in physics beyond the Standard Model and astroparticle physics. 2. On the field of string theory phenomenology, (part of which) has predicted such new light particles exist. 3. The experimental programme searching for new light particles in the UK and world-wide, by providing predictions and targets and complementary constraints.

该项目将涉及研究粒子物理学标准模型之外可能的新轻粒子的性质及其天体物理学和宇宙学特征和约束，目的是做出与高能理论（如弦理论）相关的预测，以及即将进行的实验研究。最初的目标将是可靠地计算来自超新星1987 a中微子爆发观测的卡鲁扎·克莱因引力子的约束，通过考虑等离子体混合效应（这可能会改变这些引力子与可见扇形物质的耦合常数的数量级）来校正以前的计算。弦理论模型曾（有争议地）预言这种粒子是宇宙常数的必然结果，而强化的约束可能会排除这种情况，或者为发现开辟一条道路。等离子体混合效应以前曾被考虑用于标量（自旋0）和矢量（自旋1），但这将是有史以来第一次计算自旋2粒子。该方法将涉及使用有限温度场理论的技术来解释介质中对生产率的影响，特别是在以前的工作基础上建立较低自旋情况下共振生产的可能性。根据结果，研究这种有限温度效应对卡鲁扎·克莱因引力子的宇宙学历史的影响也可能是有趣的;因为宇宙在早期非常热，这种效应可能再次导致与以前预测相比的巨大变化。这将能够精确预测暗物质遗迹中这种粒子的丰度（以前只是估计），并可能导致可以输入实验搜索程序的预测。随后，范围将扩大到考虑对其他类别的新粒子的约束，包括轴子，这是特别好的动机，以及可能的新的光标量，可能在暗能量的来源中发挥作用。同样在这种情况下，有限的温度和密度效应并没有得到一致的解释。该项目的总体影响将是1。在标准模型和天体粒子物理学之外的物理学研究人员的直接领域。2.关于弦论领域的唯象学，（其中的一部分）已经预言了这种新的轻粒子的存在。3.该实验计划通过提供预测和目标以及补充约束，在英国和世界范围内寻找新的轻粒子。