高亮度大型强子对撞机（LHC）上的四希格斯玻色子产生过程
Quadruple-Higgs boson production at the high-luminosity LHC
AI总结：
本文研究高亮度LHC中胶子融合产生四希格斯玻色子的过程，通过8个b喷注末态的唯象分析与多变量分析，获得三、四希格斯自耦合的预期约束，并探究其进入三希格斯信号区的情况，还推导了两种标准模型标量扩展下四希格斯产生的截面上限。
AI中文摘要：
我们研究高亮度大型强子对撞机（LHC）中通过胶子融合产生四希格斯玻色子的过程，针对包含8个b喷注的末态开展唯象分析，采用多变量分析方法推导对三希格斯与四希格斯玻色子自耦合修正的预期联合约束。在95%置信水平下，所得约束区间对应为-10.3<c₃<11.2和-222<d₄<234，其中c₃=κ₃-1，d₄=κ₄-1。我们还探究四希格斯玻色子产生过程如何进入要求至少6个b标记喷注的三希格斯玻色子信号区域。此外，我们考虑标准模型标量部分的两种扩展：单实标量扩展产生直接共振过程pp→S→hhhh，双实标量扩展产生级联过程pp→h₃→h₂h₂→(hh)(hh)，其中S、h₂、h₃为新标量共振；针对这些过程，我们推导了四希格斯玻色子产生截面上限随新标量质量变化的函数关系。
英文摘要：
We investigate the production of four Higgs bosons via gluon fusion at the high-luminosity LHC. We construct a phenomenological analysis of the eight-$b$-jet final state and use a multivariate analysis to derive expected simultaneous constraints on the triple and quartic Higgs boson self-coupling modifications. At 95% confidence level, the resulting region projects onto $-10.3<c_3<11.2$ and $-222<d_4<234$, where $c_3=κ_3-1$ and $d_4=κ_4-1$. We also examine how quadruple-Higgs boson production can enter a triple-Higgs boson signal region requiring at least six $b$-tagged jets. In addition, we consider two extensions of the Standard Model scalar sector: a one-real-singlet extension yielding the direct resonant process $pp\rightarrow S\rightarrow hhhh$, and a two-real-singlet extension yielding the cascade $pp\rightarrow h_3\rightarrow h_2h_2\rightarrow (hh)(hh)$, where $S$, $h_2$ and $h_3$ are new scalar resonances. For these processes, we derive expected upper limits on the quadruple-Higgs boson production cross sections as functions of the new scalar masses.
