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arXiv 1608.07282hep-phhep-ex
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LHC的$t\bar t$通道中重标量搜索的挑战和机遇

Challenges and opportunities for heavy scalar searches in the $t\bar t$ channel at the LHC

Marcela Carena, Zhen Liu

备注：
44 pages, 17 figures; v2: minor updates, reference added, match the published version on JHEP
发表信息：
JHEP11(2016)159
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摘要：

由于标准模型$t\bar t$背景的大干扰效应的特殊行为，通过$gg\rightarrow S\rightarrow t\bar t$过程的重标量和赝标量共振搜索是具有挑战性的。这种效应从信号和背景振幅之间的附加相对相位产生非平凡的线形。我们提供了微分截面的解析表达式来理解重标量信号线形状中的干扰效应。我们将我们的研究扩展到CP破坏的情况，并进一步考虑了底夸克在产生和衰变过程中的作用。我们还评估了额外的粒子对胶子融合产生过程的贡献，如停止和矢量夸克，这可能导致信号线形状的行为发生显着变化。考虑到大的干扰效应，我们在LHC进行线形搜索，并讨论了系统的不确定性和拖尾效应的重要性。我们提出了两个大型强子对撞机的性能方案，探测在各种模型中的$gg\rightarrow S \rightarrow t\bar t$通道预计的灵敏度。

英文摘要：

Heavy scalar and pseudoscalar resonance searches through the $gg\rightarrow S\rightarrow t\bar t$ process are challenging due to the peculiar behavior of the large interference effects with the standard model $t\bar t$ background. Such effects generate non-trivial lineshapes from additional relative phases between the signal and background amplitudes. We provide the analytic expressions for the differential cross sections to understand the interference effects in the heavy scalar signal lineshapes. We extend our study to the case of CP-violation and further consider the effect of bottom quarks in the production and decay processes. We also evaluate the contributions from additional particles to the gluon fusion production process, such as stops and vector-like quarks, that could lead to significant changes in the behavior of the signal lineshapes. Taking into account the large interference effects, we perform lineshape searches at the LHC and discuss the importance of the systematic uncertainties and smearing effects. We present projected sensitivities for two LHC performance scenarios to probe the $gg\rightarrow S \rightarrow t\bar t$ channel in various models.

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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