AI 中文总结
利用ATLAS探测器，通过质子 - 质子碰撞数据，测量电弱W±Z产生过程中W和Z规范玻色子极化状态，给出包含纵向极化Z玻色子事件的分数及相关截面测量结果，与标准模型预期一致。
AI 中文摘要
本文展示了在质子 - 质子碰撞中，对与两个喷注相关联的电弱W±Z产生过程（WZjj - EW）中W和Z规范玻色子极化状态的测量。数据集对应于欧洲核子研究组织大型强子对撞机上ATLAS探测器分别记录的质心能量为13 TeV和13.6 TeV的质子 - 质子碰撞的140 fb⁻¹和164 fb⁻¹的积分亮度。W±Z候选事件通过规范玻色子到电子和μ子的轻子衰变模式重建。观察到包含纵向极化Z玻色子的WZjj - EW事件在数据中的显著性为4.0个标准差。在基准区域积分测量的此类事件分数为fₓ₀ = 0.32±0.09，与电弱修正下的次领头阶标准模型预测一致。分别对具有纵向极化W玻色子的事件分数和具有两个纵向极化玻色子的事件分数设置了95%置信水平的上限0.19和0.12。还测量了√s = 13.6 TeV时WZjj - EW产生的每个轻子味的积分基准截面为σWZjj - EW→ℓ'νℓℓjj = 0.374±0.077（统计）±0.053（系统）±0.009（亮度）fb，该测量与标准模型预期一致。
英文摘要
Measurements of polarisation states of $W$ and $Z$ gauge bosons in electroweak $W^{\pm}Z$ production in association with two jets ($WZjj\mathrm{-EW}$) in proton-proton collisions are presented. The data set used corresponds to integrated luminosities of 140 fb$^{-1}$ and 164 fb$^{-1}$ of proton-proton collisions at centre-of-mass energies of 13 TeV and 13.6 TeV, respectively, recorded by the ATLAS detector at the CERN Large Hadron Collider. The $W^{\pm}Z$ candidate events are reconstructed using leptonic decay modes of the gauge bosons into electrons and muons. The observed significance for the presence in data of $WZjj\mathrm{-EW}$ events containing a longitudinally polarised $Z$ boson is of 4.0 standard deviations. The measured fraction of such events, integrated over the fiducial region, is $f_{\mathrm{X0}} = 0.32 \pm 0.09$, in agreement with the Standard Model prediction at next-to-leading-order in electroweak corrections. Upper limits at 95% confidence level of 0.19 and 0.12 are set on the fraction of events with a $W$ boson longitudinally polarised and on the fraction of events with the two bosons longitudinally polarised, respectively. The integrated fiducial cross-section per lepton flavour of $WZjj\mathrm{-EW}$ production at $\sqrt{s} = 13.6$ TeV is also measured to be $σ_{WZjj\mathrm{-EW} \rightarrow \ell^{'} ν\ell \ell jj} = 0.374 \; \pm 0.077 (\mathrm{stat.}) \; \pm 0.053 (\mathrm{syst.}) \; \pm 0.009 (\mathrm{lumi.}) \; \mathrm{fb}$, where $\ell$ and $\ell^{'}$ are either an electron or a muon. This measurement is in agreement with the Standard Model expectation.
Comments489pages in total, author list starting page 32, 6 figures, 5 tables, submitted to JHEP. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2024-03/
