arXiv 1610.088102016-10hep-phhep-ex

在$t\bar{t} Z$最终状态中的LHC矢量共振搜索

LHC vector resonance searches in the $t\bar{t} Z$ final state

Mihailo Backović, Thomas Flacke, Bithika Jain, Seung J. Lee

备注：: 37 pages, 6 figures, 9 tables. v2: typos corrected, Version published in JHEP
发表信息：: JHEP 1703 (2017) 127
DOI：: 10.1007/JHEP03(2017)127

摘要：

LHC对$l^+ l^-, \, jj, \, t\bar{t}, γγ$和$VV$末态的BSM共振的研究至今没有发现新的物理学。目前的研究结果将新物理共振的质量尺度下限设定在$\mathcal{O}(1)$ TeV范围内，假设新的共振主要衰变为一对标准模型粒子。虽然SM对搜索是对可能的新物理的重要探索，但重要的是要重新检查用这种最终状态探测的新物理场景的范围。新的共振衰减占主导地位的最终状态以外的SM对的情况下，即使理论上动机，超出了SM对搜索的范围。在本文中，我们认为，大型强子对撞机搜索（矢量）共振超过两个粒子的最终状态将是有用的补充探测新的物理方案。作为一个例子，我们考虑一类复合希格斯模型，并确定特定的模型参数点的颜色单线态，电中性矢量共振$ρ_0$衰变占主导地位的不是一对SM粒子，但一个费米子的顶部合作伙伴$T_{f1}$和顶夸克，与$T_{f1} \rightarrow tZ$。我们表明，占主导地位的衰变的$ρ_0 \rightarrow T_{f1} t$的背景下，复合希格斯模型是可能的，即使当衰变通道对$T_{f1}$是运动学开放。我们的分析涉及的情况下，$m_ρ$和$m_{T_{f1}}$的$\mathcal{O}(1)$ TeV，导致高度提升的$t\bar{t}Z$最终状态的拓扑结构。我们表明，我们认为，特定的复合希格斯粒子的情况下，可以在LHC 13与低至30 FB $^{-1}$，而被允许的其他现有的实验限制。

英文摘要：

LHC searches for BSM resonances in $l^+ l^-, \, jj, \, t\bar{t}, γγ$ and $VV$ final states have so far not resulted in discovery of new physics. Current results set lower limits on mass scales of new physics resonances well into the $\mathcal{O}(1)$ TeV range, assuming that the new resonance decays dominantly to a pair of Standard Model particles. While the SM pair searches are a vital probe of possible new physics, it is important to re-examine the scope of new physics scenarios probed with such final states. Scenarios where new resonances decay dominantly to final states other than SM pairs, even though well theoretically motivated, lie beyond the scope of SM pair searches. In this paper we argue that LHC searches for (vector) resonances beyond two particle final states would be useful complementary probes of new physics scenarios. As an example, we consider a class of composite Higgs models, and identify specific model parameter points where the color singlet, electrically neutral vector resonance $ρ_0$ decays dominantly not to a pair of SM particles, but to a fermionic top partner $T_{f1}$ and a top quark, with $T_{f1} \rightarrow tZ$. We show that dominant decays of $ρ_0 \rightarrow T_{f1} t$ in the context of Composite Higgs models are possible even when the decay channel to a pair of $T_{f1}$ is kinematically open. Our analysis deals with scenarios where both $m_ρ$ and $m_{T_{f1}}$ are of $\mathcal{O}(1)$ TeV, leading to highly boosted $t\bar{t}Z$ final state topologies. We show that the particular composite Higgs scenario we consider is discoverable at the LHC13 with as little as 30 fb$^{-1}$, while being allowed by other existing experimental constraints.

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。

摘要：

英文摘要：

相关论文