Mass splitting between charged and neutral winos at two-loop level
Mass splitting between charged and neutral winos at two-loop level
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DOI：
10.1016/j.physletb.2013.03.015
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发表时间：
2012-12
影响因子：
4.4
通讯作者：
M. Ibe;S. Matsumoto;R. Sato
中科院分区：
文献类型：
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作者：
M. Ibe;S. Matsumoto;R. Sato
最近在大型强子对撞机实验中寻找希格斯粒子的结果引起了人们对具有重费米子的超对称标准模型的更多关注。其中，几乎纯的维诺是最轻的超对称粒子（LSP）的模型已被广泛讨论，因为它们成功地提供了一个一致的暗物质候选者。wino LSP的显著唯象特征是其带电SU（2）Lpartner（带电wino）的质量简并。微小的质量分裂使带电的wino寿命很长，这使我们能够通过寻找探测器内消失的带电轨道来检测LHC实验中的wino产生。由于实验的范围对质量分裂很敏感，因此必须非常精确地估计它。因此，我们进行了全面的计算的质量分裂在两个回路的水平，并发现分裂减少了几个兆电子伏相比，一个回路的计算。这种减少导致带电的wino的寿命延长约10-30%，由此ATLAS实验对wino质量的电流约束提高约10%。
The recent result of the Higgs search at the LHC experiment has lead to more attention to the supersymmetric standard models with heavy sfermions. Among them, the models with the almost pure wino being the lightest supersymmetric particle (LSP) have been widely discussed due to their success in providing a consistent dark matter candidate. The notable phenomenological feature of the wino LSP is the degeneracy with its charged SU(2)Lpartner (the charged wino) in mass. The tiny mass splitting makes the charged wino long-lived, which allows us to detect the wino production at the LHC experiment by searching for the disappearing charged tracks inside the detectors. Since the reach of the experiment is sensitive to the mass splitting, it is mandatory to estimate it very precisely. We therefore perform a full calculation of the mass splitting at two-loop level, and find that the splitting is reduced by a few MeV compared to the one-loop calculation. This reduction leads to about a 10–30% longer lifetime of the charged wino, with which the current constraint on the wino mass by the ATLAS experiment is improved by about 10%.