Mirage mediation of supersymmetry breaking and physics at LHC

标准模型(SM)的超对称(SUSY)扩展被广泛认为是超越标准模型的最有前途的物理候选者。然而，超对称性在现实世界中被打破了。SUSY模型的大部分现象学结果实际上依赖于调节SUSY从隐形扇区向SM扇区断裂的机制。传统上，人们以各种现象学要求为线索，自下而上地研究超对称断裂的中介机制。近年来，在超弦有效超引力理论的研究中，出现了一种新的超对称断裂机制--“海市蜃楼”，引起了人们的极大关注。在这个项目中，我们试图扩展幻象调解的概念，并结合大型强子对撞机的最新实验结果研究幻影调解的现象学。主要研究结果如下：1.分析了有效超引力理论…更多具有反常U(1)规范对称性的超弦。根据Stueckelberg质量对规范玻色子质量的贡献与用来抵消FI项的SM单态的VEV之比，低能理论中的平坦方向从Green-Schwarz(GS)模到SM单态连续变化。然后，在低能理论中出现了超对称断裂机制的各种组合，其中包括海市蜃楼中介，它被描述为模数中介和异常中介的组合。我们研究了在海市蜃楼中微子作用下，在重右手中微子作用下的最小超对称中微子的轻子味破坏过程μ→eγ。结果发现，除了反常中微子的轻子味破坏外，模数和反常调解混合项中的轻子味破坏几乎被右手中微子的阈值修正所抵消，反常调解中的轻子味破坏是已知的紫外线不敏感的。那么轻子味破坏只留在模数的中介贡献上。众所周知，在海市蜃楼调解中，只要把海市蜃楼的标尺取在TeV标尺周围(TeV标尺)，就可以在没有任何微调的情况下实现比弱电标尺重一个数量级的SUSY标尺。考虑到大型强子对撞机极大地改善了超对称粒子质量的下限，以及大型强子对撞机也报道了最轻的希格斯玻色子几乎附着在最小的质量上界的迹象，我们研究了放宽TeV标度的微调标准并将超对称标度推到10TeV时的唯象后果。计算了最轻希格斯玻色子质量与超对称标度之间的关系。然后我们发现，如果最终发现β粒子超出了LHC.4的范围，那么对tan SY的测量对于计划下一代实验是极其重要的。考虑到大型强子对撞机引入的上述情况，我们研究了次极小超对称单态(NMSSM)。我们研究了电弱对称破缺的结构，并计算了最轻的希格斯玻色子的质量。我们发现，我们可以将有效的μ项(希格西诺质量)提高到比电弱标度重得多的程度，而不会恶化微调。这是因为有效μ项和下型希格斯玻色子质量之间的抵消。我们还发现，对于同时满足假真空和快子模型约束的1Te VSUSY尺度，最轻的Higgs玻色子的质量可以达到125GeV。在项目中期，LHC公布了第一个结果，表明计划中的SUSY粒子比预期的要重得多。我们将研究的重点从建立模型转移到海市蜃楼中具有自然重SUSY谱的模型的研究上，以解决暗物质过度产生的问题，并在此基础上对LHC超SY粒子的产生进行了蒙特卡罗模拟。第二和第三个结果仍然是初步的，我们正在继续研究。我们计划将这些研究作为该基金的成果发表。较少

Supersymmetric(SUSY) extension of the Standard Model(SM) is widely accepted as the most promising candidate for the physics beyond the SM. However, supersymmetry is broken in the real world. Most of the phenomenological consequences of the SUSY models actually depend on the mechanism of mediating SUSY breaking from the hidden sector to the SM sector. Traditionally, the mechanism of mediating SUSY breaking has been investigated in the bottom up approach by taking various phenomenological requirements as a clue to understand it. Recently, a new category of mechanism to mediate SUSY breaking called“mirage mediation"emerged from the study of effective supergravity theory of superstring and has been gathering a lot of attention. In this project, we tried to extend the concept of the mirage mediation and studied the phenomenology of the mirage mediation taking into account the latest experimental results from the LHC. The main results follow :1. We analyzed the effective supergravity theory … More of the superstring having the anomalous U(1) gauge symmetry. Depending on the ratio of the contributions to the gauge boson mass from the Stueckelberg mass and the vev of the SM singlet which is introduced to cancel the FI term, the flat direction in the low energy theory varies continuously from the Green-Schwarz(GS) modulus to the SM singlet. Then various combinations of the SUSY breaking mechanism appear in the low energy theory including the mirage mediation which is described as a combination of the modulus mediation and the anomaly mediation.2. We studied the lepton flavor violating process,μ→eγ, in the minimal SUSY SM(MSSM) with the heavy right-handed neutrino under the mirage mediation. It is found that lepton flavor violation in the mixing terms of the modulus and anomaly mediation is almost cancelled by the threshold correction of the right-handed neutrino, in addition to the lepton flavor violation in the anomaly mediation which is known to be UV insensitive. Then the lepton flavor violation only remains in the modulus mediation contribution.3. It is known that, in mirage mediation, the SUSY scale one order heavier than the electroweak scale can be realized without any fine-tuning by taking the mirage scale around the TeV scale(TeV scale mirage mediation). Considering the fact that the lower bound of the SUSY particle mass is drastically improved by the LHC and indications of the lightest Higgs boson almost sticking to the upper bound in the MSSM are also reported by the LHC, we investigated the phenomenological consequences when we relax the criteria of the fine-tuning in the TeV scale mirage mediation and push the SUSY scale to 10 TeV. We calculated the relation between the lightest Higgs boson mass and the SUSY scale. Then we found that the measurement of tanβis extremely important to plan the next generation experiments if the SUSY particles is eventually found to be out of the reach of the LHC.4. Taking into account the above situation introduced by the LHC, we investigated the Next-to-Minimal SUSY SM(NMSSM) in which we add a SM singlet to the MSSM. We examined the structure of the electroweak symmetry breakingand calculated the mass of the lightest Higgs boson. We found that we can rase the effectiveμterm(the higgsino mass) to considerably heavier than the electroweak scale without deteriorating the fine-tuning. This is because of the cancellation between the effectiveμterm and the down-type Higgs boson mass. We also found that the lightest Higgs boson can be as heavy as 125 GeV for 1 Te VSUSY scale simultaneously satisfying the constraint from the false vacuum and the tachyonic mode.In the middle of the project, the first result from the LHC is published and it suggested that the SUSY particles are much heavier than the expectation when this project is planned, we shifted the emphasis of the study to the study of models with natural heavy SUSY spectrum in mirage mediation from the model building to solve the problem of dark matter over production and the Monte Carlo simulation of SUSY particle production at LHC based on it. The 2nd and 3rd results are still preliminary and we are continuing the studies. We are planning to publish these researches as results of this fund. Less