AI 中文总结
本研究基于最小SU(4)/Sp(4)复合希格斯模型，利用当前LHC的希格斯耦合测量数据构建贝叶斯与频率派约束，预估未来HL-LHC和FCC-ee的测量将大幅收紧单态标量质量下限，为对撞机物理研究提供重要方向。
AI 中文摘要
我们研究了基于对称性破缺模式$\u202f\mathrm{SU}(4)\rightarrow\mathrm{Sp}(4)$的最小复合希格斯模型，该模型中电弱对称性破缺由真空对齐角$θ$主导。通过领头阶关系$κ_V=\cosθ$与$m_η=m_h/\sinθ$，希格斯粒子耦合的精确测量可直接转化为对真空结构以及单态赝南部-戈德斯通玻色子质量的约束。我们利用当前超环面仪器（ATLAS）第二轮运行（Run-2）测得的$κ_V$数据，构建了关于$θ$的贝叶斯后验分布，其中纳入了从$κ_V$到$θ$变换对应的雅可比行列式，并通过独立的频率派$Δχ^2$分析验证了结果的可靠性。随后我们将同一分析框架应用于高亮度大型强子对撞机（HL-LHC）与FCC-ee的 projected 灵敏度预估。当前数据给出单态质量在95%置信度下的保守下限约为440\u202f$\mathrm{GeV}$；而基于预估灵敏度，HL-LHC可将该下限提升至约600\u202f$\mathrm{GeV}$，FCC-ee则可将其推至2\u202f$\mathrm{TeV}$以上。贝叶斯分析与频率派分析的结果高度一致，证明了所得约束的稳健性。这些结果表明，未来的希格斯粒子精确测量将以前所未有的灵敏度探究最小$\u202f\mathrm{SU}(4)/\mathrm{Sp}(4)$复合希格斯模型的真空对齐特性，对其允许的参数空间施加愈发严格的约束，并确立单态标量粒子为未来对撞机项目极具研究价值的目标。
英文摘要
We investigate the minimal composite Higgs model based on the symmetry-breaking pattern $\mathrm{SU}(4)\rightarrow\mathrm{Sp}(4)$, where electroweak symmetry breaking is governed by the vacuum alignment angle $θ$. Through the leading-order relations $κ_V=\cosθ$ and $m_η=m_h/\sinθ$, precision measurements of Higgs couplings are translated into direct constraints on the vacuum structure and the singlet pseudo-Nambu--Goldstone boson mass. Using the current ATLAS Run-2 measurement of $κ_V$, we construct a Bayesian posterior for $θ$, including the Jacobian associated with the transformation from $κ_V$ to $θ$, and validate the results through an independent frequentist $Δχ^2$ analysis. The same framework is then applied to the projected sensitivities of the High-Luminosity LHC and FCC-ee. The current data imply a conservative lower bound of approximately $440~\mathrm{GeV}$ on the singlet mass at the $95\%$ credibility level, while the projected sensitivities improve this limit to about $600~\mathrm{GeV}$ at the HL-LHC and beyond $2~\mathrm{TeV}$ at FCC-ee. The close agreement between the Bayesian and frequentist determinations demonstrates the robustness of the extracted constraints. These results show that future Higgs precision measurements will probe the vacuum alignment of the minimal $\mathrm{SU}(4)/\mathrm{Sp}(4)$ composite Higgs model with unprecedented sensitivity, placing increasingly stringent constraints on the allowed parameter space and establishing the singlet scalar as a compelling target for upcoming collider programs.
Comments21 pages, 3 figures
