Higgs couplings at the end of 2012
Higgs couplings at the end of 2012
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DOI：
10.1007/jhep02(2013)053
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发表时间：
2013-02
影响因子：
5.4
通讯作者：
G. Belanger;B. Dumont;U. Ellwanger;J. Gunion;S. Kraml
中科院分区：
文献类型：
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作者：
G. Belanger;B. Dumont;U. Ellwanger;J. Gunion;S. Kraml
对所有公开可用的数据进行拟合，我们分析了LHC和Tevatron的最新结果在多大程度上约束了~ 125 GeV的希格斯玻色子样态的耦合。为此，我们假设只有标准模型（SM）粒子出现在希格斯衰变中，但相对于SM，树能级希格斯与上夸克、下夸克和矢量玻色子的耦合是自由参数。我们还假设相对于SM的轻子耦合与下夸克的轻子耦合相同，并且对于V= W， Z耦合具有保管对称。在最简单的方法中，根据上述参数计算胶子和光子的有效希格斯耦合。这种方法也适用于I型和II型双希格斯双重态模型。然而，我们也探索了希格斯到gg和γγ的净耦合有来自超标准模型物理的额外环路贡献的可能性。我们发现SM的p值~ 0.5与拟合的距离大于2σ，其中：a)在希格斯粒子的γγ耦合中存在一些非SM的贡献；或者b)顶夸克与希格斯粒子耦合的符号与W耦合的符号相反。在这两种情况下，p值都可以达到~ 0.9。由于选项b)很难在现实模型中实现，因此似乎更倾向于对希格斯粒子的有效耦合做出新的物理贡献。
Performing a fit to all publicly available data, we analyze the extent to which the latest results from the LHC and Tevatron constrain the couplings of the Higgs boson like state at~ 125 GeV. To this end we assume that only Standard Model (SM) particles appear in the Higgs decays, but tree-level Higgs couplings to the up-quarks, down-quarks and vector bosons, relative to the SM are free parameters. We also assume that the leptonic couplings relative to the SM are the same as for the down-quark, and a custodial symmetry for the V= W, Z couplings. In the simplest approach, the effective Higgs couplings to gluons and photons are computed in terms of the previous parameters. This approach is also applied to Two-Higgs-Doublet Models of Type I and Type II. However, we also explore the possibility that the net Higgs to gg and γγ couplings have extra loop contributions coming from Beyond-the-Standard Model physics. We find that the SM p-value~ 0.5 is more than 2σ away from fits in which: a) there is some non-SM contribution to the γγ coupling of the Higgs; or b) the sign of the top quark coupling to the Higgs is opposite that of the W coupling. In both these cases p-values~ 0.9 can be achieved. Since option b) is difficult to realize in realistic models, it would seem that new physics contributions to the effective couplings of the Higgs are preferred.