The exotic decay modes of the already discovered 125-GeV scalar into a pair of light pseudoscalars are a good probe of those new physics scenarios where such pseudoscalars exist. Searches in the mass region where the pseudoscalar (A) is lighter than 62.5 GeV have yielded null findings so far. No search has yet examined mA>62.5 GeV where the cross section is suppressed by the off-shell pseudoscalar. We point out a possible enhancement of the sensitivity of probing hAA coupling in the context of a Type-X two Higgs doublet model. We focus on h→AA(⁎)→4τ, and select events with two same-sign τ-jets along with a pair of same-sign leptons. This enables much more effective background elimination than in the erstwhile proposed channels. Taking two values of the ττA coupling into account, we obtain limits on the hAA coupling that can be probed at 2σ and 3σ significance, for mA ranging up to 85 GeV. For mA<62.5 GeV, too, we find the probe through our suggested channel exhibits considerable improvement upon the usual 2μ2τ-based searches conducted at the LHC. Within this region, achieving the reach of λhAA coupling at 3000 fb−1 luminosity using our strategy would require approximately ∼3.6×105 fb−1 luminosity using conventional 2μ2τ-based searches.

中文翻译：

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改进 Type-X 两个希格斯双峰模型场景中 hAA 耦合的探针：τ-jet 电荷识别的关键作用


已发现的 125 GeV 标量到一对光赝标量的奇特衰变模式是对存在此类赝标量的新物理场景的良好探索。迄今为止，在赝标量 (A) 轻于 62.5 GeV 的质量区域中进行的搜索尚未得出任何结果。尚未进行任何搜索检查 mA>62.5 GeV，其中横截面被离壳赝标量抑制。我们指出在 X 型双希格斯双峰模型的背景下探测 hAA 耦合的灵敏度可能会增强。我们关注 h→AA(⁎)→4τ，并选择具有两个同号 τ 射流和一对同号轻子的事件。与以前提出的通道相比，这可以更有效地消除背景。考虑到 ττA 耦合的两个值，我们获得了 hAA 耦合的限制，可以在 2σ 和 3σ 显着性下探测到 mA 范围高达 85 GeV。对于 mA<62.5 GeV，我们也发现通过我们建议的通道进行的探测器比在大型强子对撞机上进行的通常基于 2μ2τ 的搜索表现出相当大的改进。在这个区域内，使用我们的策略在 3000 fb−1 光度下实现 λhAA 耦合的范围将需要使用传统的基于 2μ2τ 的搜索约 ∼3.6×105 fb−1 光度。