We discuss a possibility that the parameter space of the two Higgs doublet model is significantly narrowed down by considering the synergy between direct searches for additional Higgs bosons at the LHC and its luminosity upgraded operation and precision measurements of the Higgs boson properties at future electron-positron colliders such as the International Linear Collider. We show that, in the case where the coupling constants of the discovered Higgs boson are slightly different from the predicted values in the standard model, most of the parameter space is explored by the direct searches of extra Higgs bosons, in particular for the decays of the extra Higgs bosons into the discovered Higgs boson, and also by the theoretical arguments such as perturbative unitarity and vacuum stability. This can be done because there appears an upper limit on the mass of the extra Higgs bosons as long as the deviation exists in the Higgs boson coupling. We also show that in the alignment limit where all the Higgs boson couplings take the standard model like values most of the parameter space cannot be excluded because most of the Higgs to Higgs decays are suppressed and also there is no upper limit on the masses from the theoretical arguments.

我们讨论了通过考虑在大型强子对撞机直接搜索额外的希格斯玻色子及其光度提升操作与未来电子正电子希格斯玻色子性质的精确测量之间的协同作用，两个希格斯二重态模型的参数空间显着缩小的可能性对撞机，例如国际直线对撞机。我们发现，在发现的希格斯玻色子的耦合常数与标准模型中的预测值略有不同的情况下，大部分参数空间是通过额外希格斯玻色子的直接搜索来探索的，尤其是对于衰变的希格斯玻色子。多余的希格斯玻色子进入发现的希格斯玻色子，并且还受到诸如扰动统一性和真空稳定性等理论论证的影响。之所以可以这样做，是因为只要希格斯玻色子耦合中存在偏差，额外希格斯玻色子的质量就会出现上限。我们还表明，在所有希格斯玻色子耦合均采用标准模型（如值）的对准极限中，由于大多数希格斯到希格斯衰减都被抑制，并且没有质量上限，因此无法排除大多数参数空间理论论证。