AI 中文总结
ATLAS合作组利用13 TeV和13.6 TeV的pp对撞数据，结合多末态搜索结果，对tH产生进行测量，未发现显著超出，联合测量为迄今最精确的tH产生测量
AI 中文摘要
本文介绍了一项对希格斯玻色子与单个顶夸克伴随产生的搜索，该搜索针对包含τ轻子的多轻子末态，使用了大型强子对撞机（LHC）上ATLAS探测器收集的质心系能量√s=13 TeV的质子-质子对撞数据，积分亮度为140 fb⁻¹。分析目标为H→ττ衰变，其中至少一个τ轻子发生强子衰变，以指示希格斯玻色子的存在。未观测到超出预期本底的显著超出，且在95%置信水平下，观测到的（预期的）信号强度上限被设定为标准模型预测值的8.6（9.3）倍。该测量结果与ATLAS合作组之前针对同一产生过程但不同末态的已发表结果相结合，使用了√s=13 TeV的质子-质子对撞数据（积分亮度140 fb⁻¹）和√s=13.6 TeV的质子-质子对撞数据（积分亮度164 fb⁻¹）。信号强度的联合测量结果为μ_tH = 3.3⁺¹.⁷₋₁.₅ = 3.3 ± 1.2（统计）⁺¹.¹₋₁.₀（系统）倍的标准模型预期，对应观测到的（预期的）tH显著性为2.3（0.8）个标准偏差。在95%置信水平下，联合观测到的（预期的）信号强度上限被设定为标准模型预测值的6.1（2.7）倍。该联合分析代表了迄今为止对tH产生的最精确测量。
英文摘要
A search for the production of a Higgs boson in association with a single top quark in multi-lepton final states including $τ$-leptons is presented, using an integrated luminosity of $140\,\text{fb}^{-1}$ of proton-proton collision data at a centre-of-mass energy of $\sqrt{s} = 13\,\text{TeV}$ collected by the ATLAS detector at the LHC. The analysis targets the $H \to ττ$ decay, where at least one $τ$-lepton decays hadronically, to indicate the presence of the Higgs boson. No significant excess over the expected background is observed, and an observed (expected) upper limit at the 95% confidence level on the signal strength is set at 8.6 (9.3) times the Standard Model prediction. This measurement is combined with previous publications of the ATLAS Collaboration targeting the same production process but in different final states, using $140\,\text{fb}^{-1}$ of proton-proton collision data at $\sqrt{s} = 13\,\text{TeV}$ and $164\,\text{fb}^{-1}$ at $13.6\,\text{TeV}$. The combined measurement of the signal strength yields $μ_{tH} = 3.3^{+1.7}_{-1.5} = 3.3 \pm 1.2\,(\text{stat.})^{+1.1}_{-1.0}\,(\text{sys.})$ times the Standard Model expectation, corresponding to an observed (expected) $\textit{tH}$ significance of 2.3 (0.8) standard deviations. The combined observed (expected) upper limit at the 95% confidence level on the signal strength is set at 6.1 (2.7) times the Standard Model prediction. This combination represents the most precise measurement of $tH$ production to date.
Comments50 pages in total, author list starting at page 33, 12 figures, 8 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGP-2026-05/
