论文标题
使用$ \ sqrt {s} = 13 $ tev使用Atlas实验的DiLepton事件在Top-Quark衰减中产生的$ W $玻色子的两极分化的测量
Measurement of the polarisation of $W$ bosons produced in top-quark decays using dilepton events at $\sqrt{s} = 13$ TeV with the ATLAS experiment
论文作者
论文摘要
提出了质子 - 普罗顿碰撞数据在$ \ sqrt {s} = 13 $ tev的质量中，对$ w $ boson的极化的测量进行了测量。数据是由Atlas检测器在大型强子对撞机上收集的，对应于139 fb $^{ - 1} $的集成光度。进行测量，以选择$ t \ bar {t} $事件，并用两个带电的瘦素（电子或MUON）和至少两个$ b $标记的喷气机腐烂到最终状态。 The polarisation is extracted from the differential cross-section distribution of the $\cos{θ^{*}}$ variable, where $θ^{*}$ is the angle between the momentum direction of the charged lepton from the $W$ boson decay and the reversed momentum direction of the $b$-quark from the top-quark decay, both calculated in the $W$ boson rest frame.针对检测器的接受和分辨率校正了Parton级别的结果，以$ \ cos {θ^{*}} $ angle提出。发现纵向，左和右极化状态的测量分数为$ f_ {0} = 0.684 \ pm 0.005 \，\ Mathrm {（stat。 0.003 \，\ Mathrm {（stat。）} \ pm 0.008 \，\ Mathrm {（syst。）} $和$ f _ {\ Mathrm {\ Mathrm {r}} = -0.002 \ 0.002 \ pm 0.002 \ pm pm 0.002 \，，\ Mathrm {（stat。与标准模型预测。
A measurement of the polarisation of $W$ bosons produced in top-quark decays is presented, using proton-proton collision data at a centre-of-mass energy of $\sqrt{s} = 13$ TeV. The data were collected by the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 139 fb$^{-1}$. The measurement is performed selecting $t\bar{t}$ events decaying into final states with two charged leptons (electrons or muons) and at least two $b$-tagged jets. The polarisation is extracted from the differential cross-section distribution of the $\cos{θ^{*}}$ variable, where $θ^{*}$ is the angle between the momentum direction of the charged lepton from the $W$ boson decay and the reversed momentum direction of the $b$-quark from the top-quark decay, both calculated in the $W$ boson rest frame. Parton-level results, corrected for the detector acceptance and resolution, are presented for the $\cos{θ^{*}}$ angle. The measured fractions of longitudinal, left- and right-handed polarisation states are found to be $f_{0} = 0.684 \pm 0.005\,\mathrm{(stat.)} \pm 0.014\,\mathrm{(syst.)}$, $f_{\mathrm{L}} = 0.318 \pm 0.003\,\mathrm{(stat.)} \pm 0.008\,\mathrm{(syst.)}$ and $f_{\mathrm{R}} = -0.002 \pm 0.002\,\mathrm{(stat.)} \pm 0.014\,\mathrm{(syst.)}$, in agreement with the Standard Model prediction.
