arXiv 2203.017342022-03hep-ph

在LHC上探测类轴子粒子与胶子的耦合

Probing axion-like particles coupling to gluons at the LHC

Filmon Andom Ghebretinsaea, Zeren Simon Wang, Kechen Wang

备注：: 24 pages, 10 figures, 3 tables
发表信息：: https://link.springer.com/article/10.1007/JHEP07(2022)070
DOI：: 10.1007/JHEP07(2022)070

摘要：

假设ALP只与胶子耦合，它们可以通过$p p \to a j$过程产生，并在大型强子对撞机上衰变为两个喷流。当耦合参数$C_{\tilde{G}} / f_a$较小时，ALP的寿命可以足够长，导致位移的末态喷流。在本文中，我们考虑的信号，包括及时和长寿的情况下，通过采用专门的Delphes模块来处理流离失所的喷气机的ALP。在检测器级别生成和模拟相关背景过程，并执行基于机器学习的多变量分析，以区分信号和背景事件，并实现最佳灵敏度。基于这项研究积累的数据，我们预测的预期上限$C_{\tilde{G}}/f_a$的ALP质量$m_a$在5 $-$ 2300 GeV的范围内，在2-，3-和5- $σ$的意义在高亮度LHC与14 TeV的质心能量和3 ab $^{-1}$集成光度。在$C_{\tilde{G}}/f_a$和$m_a$跨越的参数空间中的巨大的以前未探测的区域进行探测，并发现在2- $σ$意义上的$C_{\tilde{G}}/f_a$的最佳上限是$1.0 \times 10^{-2} \,\, {\rm TeV^{-1}}$周围的$m_a \sim 500$ GeV。ALP质量重建从运动学的最终状态喷流，我们发现，它是可测量的，在这种方法时，$m_a$是低于约1 TeV的HL-LHC。系统的不确定性和验证的EFT框架的影响也检查和讨论。

英文摘要：

Assuming ALPs couple to gluons only, they can be produced via the $p p \to a j$ process and decay into two jets at the LHC. When the coupling parameter, $C_{\tilde{G}} / f_a$, is small, the lifetime of ALPs can be long enough leading to displaced final state jets. In this paper, we consider the signal including both the prompt and long-lived cases of ALPs by employing a specialized Delphes module to handle displaced jets. Relevant background processes are generated and simulated at the detector level, and multivariate analyses based on machine-learning are performed to discriminate signal and background events and achieve the best sensitivities. Based on the data accumulated for this study, we forecast the expected upper limits on $C_{\tilde{G}}/f_a$ for ALP mass $m_a$ in the range 5$-$2300 GeV at 2-, 3- and 5-$σ$ significances at the High Luminosity-LHC with 14 TeV center-of-mass energy and 3 ab$^{-1}$ integrated luminosity. Vast previously unprobed regions in the parameter space spanned by $C_{\tilde{G}}/f_a$ and $m_a$ are probed and the best upper limits on $C_{\tilde{G}}/f_a$ at 2-$σ$ significance is found to be around $1.0 \times 10^{-2} \,\, {\rm TeV^{-1}}$ for $m_a \sim 500$ GeV. The ALP mass is reconstructed from the kinematics of final state jets and we find that it is measurable in this method when $m_a$ is below about 1 TeV at the HL-LHC. The effects of systematic uncertainties and validation of the EFT framework are also checked and discussed.

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：

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