The minimal model of nonbaryonic dark matter: A singlet scalar
The minimal model of nonbaryonic dark matter: A singlet scalar
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DOI：
10.1016/s0550-3213(01)00513-2
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发表时间：
2000-11
期刊：
影响因子：
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通讯作者：
C. Burgess;C. Burgess;M. Pospelov;T. Veldhuis
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文献类型：
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作者：
C. Burgess;C. Burgess;M. Pospelov;T. Veldhuis
我们提出了标准模型最简单的可重整化扩展——仅添加一个单线态标量场——作为非重子暗物质的极简模型。除了标准模型中已经出现的参数之外，这种模型的特征仅在于三个参数：无量纲自耦合和新标量的质量，以及与希格斯场的无量纲耦合 λ。如果单线态是暗物质，这些参数通过宇宙丰度约束彼此相关，这意味着单线态与希格斯场的耦合很大，λ∼O(0.1-1)。由于该参数还控制与普通物质的耦合，因此我们获得了对具有原子核的单线态的弹性横截面的预测。由此产生的散射率接近直接和间接搜索的当前极限。单线态的存在也对当前的希格斯粒子搜索产生影响，因为它对大部分参数空间的不可见希格斯宽度做出了很大贡献。这些标量可以在 Spergel 和 Steinhardt 最近提出的宇宙学意义上的强自耦合，但仅限于非常低的质量 (≲1 GeV)，这只有以参数的一些微调为代价才可能实现。
We propose the simplest possible renormalizable extension of the Standard Model—the addition of just one singlet scalar field—as a minimalist model for nonbaryonic dark matter. Such a model is characterized by only three parameters in addition to those already appearing within the Standard Model: a dimensionless self-coupling and a mass for the new scalar, and a dimensionless coupling, λ, to the Higgs field. If the singlet is the dark matter, these parameters are related to one another by the cosmological abundance constraint, implying that the coupling of the singlet to the Higgs field is large, λ∼O(0.1–1). Since this parameter also controls couplings to ordinary matter, we obtain predictions for the elastic cross section of the singlet with nuclei. The resulting scattering rates are close to current limits from both direct and indirect searches. The existence of the singlet also has implications for current Higgs searches, as it gives a large contribution to the invisible Higgs width for much of parameter space. These scalars can be strongly self-coupled in the cosmologically interesting sense recently proposed by Spergel and Steinhardt, but only for very low masses (≲1 GeV), which is possible only at the expense of some fine-tuning of parameters.