标题： II型双希格斯二重态模型中希格斯粒子对产生和重希格斯搜索的基准测试 显示英文标题

标题： Benchmarks for Higgs Pair Production and Heavy Higgs Searches in the Two-Higgs-Doublet Model of Type II

摘要： 寻找额外的希格斯粒子以及精确测量希格斯（自）耦合是未来对撞机实验的主要目标。在本文中，我们研究了在类型II的$CP$守恒的双希格斯二重态模型背景下，这些搜索中新物理信号的可能大小。利用来自味、电弱精度和希格斯信号强度数据的当前限制，我们确定了三重希格斯耦合和重希格斯玻色子衰变为轻希格斯玻色子的分支比的允许大小。将观测到的希格斯共振与轻的$CP$偶的2HDM希格斯玻色子$h$相匹配，我们发现$hhh$耦合不能超过其标准模型值，但在2$\sigma$水平上可以减少因子$0.56$。 重中性Higgs玻色子$H$和$A$分裂为两个费米子或两个矢量玻色子末态的分支分数可以分别减少因子$0.4$和$0.01$，如果可能衰变为较轻的Higgs玻色子，并且衰变Higgs的质量低于$t\bar t$阈值。 为了便于未来在具有大三重Higgs耦合或超出标准模型Higgs搜索范围的重Higgs玻色子衰变模式的2HDM情景中的对撞机特征研究，我们提供了一组具有这些特性的基准点，并符合所有当前约束。 我们还讨论了重Higgs玻色子对某些基准点在14 TeV LHC上的$gg\to hh$截面的影响。 对于低于$m_H$阈值的$hh$，由于破坏性干涉导致 SM$gg\to hh$交叉截面减少，但对于高于$m_H$阈值的$hh$，当前约束允许增强因子超过50。 在重希格斯粒子在300 fb${}^{-1}$数据后不会被标准搜索发现的情况下，增强因子6仍然有可能。 显示英文摘要

摘要： The search for additional Higgs particles and the exact measurements of Higgs (self-) couplings is a major goal of future collider experiments. In this paper we investigate the possible sizes of new physics signals in these searches in the context of the $CP$-conserving two-Higgs doublet model of type II. Using current constraints from flavour, electroweak precision, and Higgs signal strength data, we determine the allowed sizes of the triple Higgs couplings and the branching fractions of the heavy Higgs bosons into lighter Higgs bosons. Identifying the observed Higgs resonance with the light $CP$-even 2HDM Higgs boson $h$, we find that the $hhh$ coupling cannot exceed its SM value, but can be reduced by a factor of $0.56$ at the 2 $\sigma$ level. The branching fractions of the heavy neutral Higgs bosons $H$ and $A$ into two-fermion or two-vector-boson final states can be reduced by factors of $0.4$ and $0.01$, respectively, if decays into lighter Higgs boson are possible and if the mass of the decaying Higgs is below the $t\bar t$ threshold. To facilitate future studies of collider signatures in 2HDM scenarios with large triple Higgs couplings or decay modes of the heavy Higgs bosons not covered by the SM Higgs searches we provide a set of benchmark points which exhibit these features and agree with all current constraints. We also discuss the effect of the heavy Higgs bosons on the $gg\to hh$ cross section at a 14 TeV LHC for some of these benchmarks. For $m_H$ below the $hh$ threshold we see a reduction of the SM $gg\to hh$ cross section due to destructive interference, but for $m_H$ above the $hh$ threshold current constraints allow enhancement factors above 50. An enhancement factor of 6 is still possible in scenarios in which the heavy Higgs particles would not be discovered by standard searches after 300 fb${}^{-1}$ of data.