arXiv 1507.060182015-07-22hep-ph

低尺度复合Higgs模型和1.8 $\sim$ 2 TeV Diboson过剩

Low Scale Composite Higgs Model and 1.8 $\sim$ 2 TeV Diboson Excess

Ligong Bian, Da Liu, Jing Shu

备注：: 9 pages, 3 figures, 3 tables

摘要：

我们认为一个简单的解决方案来解释最近的diboson过量观察ATALS和CMS合作模型保管对称$SU(2)_L \times SU(2)_R \rightarrow SU(2)_c$。质量范围为$1.8 \sim 2$ TeV的$SU(2)_L$三重态矢量玻色子$ρ$将通过具有相当大的二玻色子衰变分支的Drell-Yan过程产生，以解释过量。另一个$SU(2)_L \times SU(2)_R$双重轴矢量玻色子$a$将抵消所有由$ρ$引起的电弱观测偏差，即使SM费米子与一些耦合到$ρ$的重矢量类（复合）费米子混合（“非普遍部分复合”），因此允许每个SM费米子与$ρ$之间的任意耦合。我们在“广义复合Higgs”框架下提出了我们的模型，其中$SO(5) \times U(1)_X \rightarrow SO(4) \times U(1)_X$在$f$尺度上破缺，并要求第一温伯格求和规则和正规范玻色子形状因子作为理论约束。我们发现，如果左手SM轻夸克，带电轻子和顶部有零，零/适度的小和中等/大的复合成分的$g_ρ$和$f$的合理值，我们的模型可以很好地拟合diboson过剩。树级$S$参数和$h \rightarrow Z γ$之间的相关性表明，$a$对$h \rightarrow Z γ$有很大的贡献，而且在我们的参数空间中，它确实是一种$\mathcal{O}(1)$效应，如果这种双玻色子过剩被$13 \sim 14$ TeV LHC运行II证实，它为我们的场景提供了一个强有力的暗示。

英文摘要：

We consider a simple solution to explain the recent diboson excess observed by ATALS and CMS Collaborations in models with custodial symmetry $SU(2)_L \times SU(2)_R \rightarrow SU(2)_c$. The $SU(2)_L$ triplet vector boson $ρ$ with mass range of $1.8 \sim 2$ TeV would be produced through the Drell-Yan process with sizable diboson decay branching to account for the excess. The other $SU(2)_L \times SU(2)_R$ bidoublet axial vector boson $a$ would cancel all deviations of electroweak obervables induced by $ρ$ even if the SM fermions mix with some heavy vector like (composite) fermions which couple to $ρ$ ("non-universally partially composite"), therefore allows arbitrary couplings between each SM fermion and $ρ$. We present our model in the "General Composite Higgs" framework with $SO(5) \times U(1)_X \rightarrow SO(4) \times U(1)_X$ breaking at scale $f$ and demand the first Weinberg sum rule and positive gauge boson form factors as the theoretical constraints. We find that our model can fit the diboson excess very well if the left-handed SM light quarks, charged leptons and tops have zero, zero/moderately small and moderate/large composite components for reasonable values of $g_ρ$ and $f$. The correlation between tree level $S$ parameter and the $h \rightarrow Z γ$ suggest a large $a$ contribution to $h \rightarrow Z γ$ and it is indeed a $\mathcal{O}(1)$ effect in our parameter space which provides a strong hint for our scenario if this diboson excess is confirmed by the $13 \sim 14$ TeV LHC Run II.

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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英文摘要：

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