AI 中文总结
该研究在3 TeV CLIC上针对II型双希格斯二重态模型，分析类矢量底夸克单产生过程的半轻子末态，发现多变量分析可提升信号本底分离度，1.3-1.5 TeV的B夸克情景预期显著性超5σ。
AI 中文摘要
我们研究质心系能量√s=3 TeV的紧凑型线性对撞机（Compact Linear Collider, CLIC）在扩展了类矢量夸克的II型双希格斯二重态模型中，对类矢量底夸克的单电弱产生过程的灵敏度。我们考虑的过程为e⁺e⁻→Bḇ+ḇB，其中B→φb（φ为H或A），且φ→t̄t。我们聚焦于包含1个带电轻子、缺失横动量、4个b标记喷注和2个轻喷注的半轻子末态，该道可直接探测扩展夸克与希格斯领域的相互作用。在应用理论约束、电弱精确约束、希格斯领域限制及现有对撞机限制后，我们开展了探测器级的事例选择和多变量分析。事例选择分析在积分亮度为5 ab⁻¹时仍未达到发现灵敏度，而多层感知机和XGBoost分类器可大幅改善信号与本底的分离度。对于B夸克质量m_B≈1.3~1.5 TeV的可行情景，即使本底归一化存在15%的不确定度，预期显著性仍高于5σ。
英文摘要
We study the sensitivity of the Compact Linear Collider at $\sqrt{s}=3~\mathrm{TeV}$ to the single electroweak production of a vector-like bottom quark in a type-II Two-Higgs-Doublet Model extended by vector-like quarks. We consider the process $e^+e^-\to B\bar b+\bar B b$, followed by $B\toϕb$ with $ϕ=H,A$ and $ϕ\to t\bar t$. We focus on the semileptonic final state with one charged lepton, missing transverse momentum, four $b$-tagged jets, and two light jets. This channel directly probes the interplay between the extended quark and Higgs sectors. After applying theoretical constraints, electroweak precision constraints, Higgs-sector bounds, and current collider limits, we perform detector-level cut-based and multivariate analyses. The cut-based analysis remains below discovery sensitivity at $5~\mathrm{ab}^{-1}$, while a multilayer perceptron and an XGBoost classifier provide substantially improved signal-background separation. For viable scenarios with $m_B\simeq1.3$--$1.5~\mathrm{TeV}$, the expected significance remains above $5σ$ even for a $15\%$ uncertainty on the background normalization.
