arXiv 1402.54032014-02hep-ph

具有U（1）R轻子数的超对称模型的电弱精确测量

Electroweak precision measurements in supersymmetric models with a U(1)R lepton number

Hugues Beauchesne, Thomas Gregoire

备注：: 18 pages, 6 figures, references added
DOI：: 10.1007/JHEP05(2014)051

摘要：

随着实验对MSSM参数空间的约束及其密切变化变得更强，探索挑战MSSM一些标准假设的超对称模型的动机也变得更强。例如，高吉诺是狄拉克而不是马约拉纳的模型最近受到了更多的关注。除了允许超软超对称性破坏机制，其中的gauginos只提供有限的阈值校正标量质量，截面的夸克对的生产减少。此外，狄拉克高吉诺可以用来建立具有U（1）R对称性的模型。然后可以用轻子数来识别这种对称性，从而得出与传统情况截然不同的模型。在这些模型中，超中微子可以获得一个vev，并给予轻子和下型夸克质量。这种现象是新颖的，结合签名，是典型的R-宇称违反的情况下产生的签名leptoquark。相应地，来自弱电精密数据的约束也不同。在这些模型中，轻子与高吉诺和超势汤川耦合的混合可以在树水平上对EWPM做出贡献。此外，轻子普适性被打破。本文采用Han和Skiba [1]的算符分析方法，考虑轻子普适性的相关破坏，并对模型进行了整体拟合，得到了包含所有相关的树级和环级效应的电弱精确数据。我们得到了超中微子的vev和模型的超势耦合的界。

英文摘要：

As experimental constraints on the parameter space of the MSSM and close variations thereof become stronger, the motivation to explore supersymmetric models that challenge some of the standard assumptions of the MSSM also become stronger. For example, models where the gauginos are Dirac instead of Majorana have recently received more attention. Beside allowing for a supersoft SUSY breaking mechanism where the gauginos only provide finite threshold corrections to scalar masses, the cross section for the production of a squark pairs is reduced. In addition, Dirac gauginos can be used to build models that possess a U(1)R symmetry. This symmetry can then be identified with a lepton number, leading to models that are quite different from conventional scenarios. The sneutrinos in these models can acquire a vev and give mass to the leptons and the down-type squark. The phenomenology is novel, combining signatures that are typical of R-parity violating scenarios with signatures arising from leptoquarks. Correspondingly the constraints from electroweak precision data are also different. In these models, one of the leptons mixes with gauginos and superpotential Yukawa couplings can contribute to EWPM at tree level. In addition, lepton universality is broken. In this paper we adapt the operators analysis of Han and Skiba [1] to include the relevant violation of lepton universality, and do a global fit of the model to electroweak precision data, including all relevant tree-level and loop-level effects. We obtain bounds on the vev of the sneutrino and on the superpotential couplings of the model.

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。

摘要：

英文摘要：

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