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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在 Type - X 两个 Higgs 双峰模型场景中改进 hAA 耦合探针：τ 射流电荷识别的关键作用


已经发现的 125-GeV 标量的奇异衰变模式转化为一对光伪标量，很好地探测了存在此类伪标量的那些新物理场景。到目前为止，在伪标量 （A） 轻于 62.5 GeV 的质量区域中进行搜索，结果为零。尚未进行搜索检查 mA>62.5 GeV，其中横截面被脱壳伪标量抑制。我们指出，在 Type X 两个 Higgs 双峰模型的背景下，探测 hAA 耦合的灵敏度可能会增强。我们专注于 h→AA（⁎）→4τ，并选择具有两个同号 τ 喷流和一对同号轻子的事件。这比以前提议的渠道更有效地消除背景。考虑到 ττA 耦合的两个值，我们获得了 hAA 耦合的限值，可以在 2σ 和 3σ 显著性处探测，mA 范围高达 85 GeV。对于 mA<62.5 GeV，我们发现通过我们建议的通道的探针比通常在 LHC 进行的基于 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，使用传统的基于 2μ2τ 的搜索大约需要大约 ∼3.6×105 fb-1 光度。