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arXiv 1012.2060hep-ph
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SU(6)/Sp(6)小Higgs模型中的UV友好T宇称

UV friendly T-parity in the SU(6)/Sp(6) little Higgs model

Tom Brown, Claudia Frugiuele, Thomas Gregoire

摘要:

电弱精确测试对小希格斯模型的参数空间提出了严格的限制。在一般的小希格斯模型中,TeV尺度粒子的树级交换产生了高维算子,这些算子对通常太大的电弱观测量做出了贡献。为了避免这个问题,可以引入称为T宇称的离散对称来禁止危险的耦合。然而,人们意识到,在简单的群模型中,如最小希格斯模型,在UV完成中实现T宇称可能会带来一些挑战。这种情况类似于QCD中的情况,在QCD中,π介子可以很容易地被定义为手征拉格朗日量中新的$Z_2$对称下的奇数,但是这个$Z_2$不是夸克拉格朗日量的对称。在本文中,我们研究的可能性,实现T-宇称的低能量$SU(6)/Sp(6)$模型,可能更容易实现在紫外线。在我们的模型中,T宇称对低能非线性西格玛模型场的作用方式不同于最初对最小希格斯粒子的作用方式,从而导致了一个不同的低能理论.特别是,这个模型的希格斯部门是一个惰性的两个希格斯偶极子模型与近似保管对称。我们检查的贡献模型的各个部门的电弱精密数据,和暗物质丰度。

英文摘要:

Electroweak precision tests put stringent constraints on the parameter space of little Higgs models. Tree-level exchange of TeV scale particles in a generic little Higgs model produce higher dimensional operators that make contributions to electroweak observables that are typically too large. To avoid this problem a discrete symmetry dubbed T-parity can be introduced to forbid the dangerous couplings. However, it was realized that in simple group models such as the littlest Higgs model, the implementation of T-parity in a UV completion could present some challenges. The situation is analogous to the one in QCD where the pion can easily be defined as being odd under a new $Z_2$ symmetry in the chiral Lagrangian, but this $Z_2$ is not a symmetry of the quark Lagrangian. In this paper we examine the possibility of implementing a T-parity in the low energy $SU(6)/Sp(6)$ model that might be easier to realize in the UV. In our model, the T-parity acts on the low energy non-linear sigma model field in way which is different to what was originally proposed for the Littlest Higgs, and lead to a different low energy theory. In particular, the Higgs sector of this model is a inert two Higgs doublets model with an approximate custodial symmetry. We examine the contributions of the various sectors of the model to electroweak precision data, and to the dark matter abundance.

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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