AI 中文总结
该研究利用FCC-hh的$ZZγ$产生，通过$\ell\ell\nu\nu\gamma$末态探测反常四次规范耦合，采用探测器模拟及多元技术分离信号，计算预期显著性，给出相关耦合的95%置信水平限制，相比LHC极限有数量级提升。
AI 中文摘要
本研究通过100 TeV质子-质子未来环形对撞机-强子-强子（FCC-hh）中$pp→ZZγ$产生，对反常四次规范耦合（aQGCs）进行了灵敏度预测，积分亮度为30 ab⁻¹。考虑的$\ell\ell\nu\nu\gamma$末态由一个$Z$玻色子产生的同味、异号轻子对（电子或μ子）、另一个$Z$玻色子向中微子的不可见衰变以及一个伴随光子组成。通过实际探测器模拟纳入FCC-hh探测器响应及其对重建对象的影响。采用三种多元技术从相关标准模型背景中分离信号。通过对系统总横向质量（$M_T^{tot}$）的严格、依赖算符的限制来保持幺正性。在阿西莫夫近似下，针对一次变化一个反常耦合以及0%至10%的背景系统不确定性，计算了预期显著性中位数。深度神经网络方法具有最高的分离能力。在无系统不确定性的组合$e + μ$通道中，对$|f_{T0}/\Lambda^{4}|$、$|f_{T8}/\Lambda^{4}|$、$|f_{T9}/\Lambda^{4}|$和$|f_{M2}/\Lambda^{4}|$的95%置信水平限制分别为$2.83×10^{-3}$、$1.65×10^{-3}$、$3.81×10^{-3}$和$8.97×10^{-3}$ TeV⁻⁴。与当前LHC极限相比，在假设5%系统不确定性的情况下有一个数量级的提升。
英文摘要
In this study, the sensitivity to anomalous quartic gauge couplings (aQGCs) is projected via $pp \rightarrow ZZγ$ production in the 100 TeV proton-proton Future Circular Collider - hadron-hadron (FCC-hh) for an integrated luminosity of 30 ab$^{-1}$. The $\ell\ellννγ$ final state under consideration consists of a same-flavor, opposite-sign lepton pair (electrons or muons) from one $Z$ boson, the invisible decay of the other $Z$ boson into neutrinos, and an accompanying photon. The FCC-hh detector response and its effects on the reconstructed objects are included through a realistic detector simulation. Three multivariate techniques are employed to separate the signal from the relevant SM backgrounds. Unitarity is preserved by a strict, operator-dependent bound on the total transverse mass ($M_T^{tot}$) of the system. The median expected significances are calculated within the Asimov approximation for one anomalous coupling varied at a time and for background systematic uncertainties between 0\% and 10\%. The highest separation power is obtained with the deep neural network method. The resulting 95\% confidence level limits on $|f_{T0}/Λ^{4}|$, $|f_{T8}/Λ^{4}|$, $|f_{T9}/Λ^{4}|$ and $|f_{M2}/Λ^{4}|$ in the combined $e+μ$ channel without systematic uncertainties are $2.83\times 10^{-3}$, $1.65\times 10^{-3}$, $3.81\times 10^{-3}$ and $8.97\times 10^{-3}$ TeV$^{-4}$, respectively. We have an order of magnitude improvement when compared to current LHC limits with the assumption of 5\% systematic uncertainty.
Comments14 pages, 8 figures
