论文标题
$ 4
$t\bar tZ$ in the $4\ell$ channel at NLO in QCD
论文作者
论文摘要
nlo qcd校正$ pp \ rightarrow e^+v+ν_eμ^ - \barν_μτ^+τ^+τ^-b \ bar {b}+x $呈现，其中包含完整的外壳效果。该计算包括所有共振和非谐音Feynman图，光子和$ z $ - 高速玻色子的贡献以及干扰效应，所有这些都在矩阵元素级别上掺入。此外，通过BREIT-WIGNER传播器描述了所有沉重的中间颗粒。在综合和差异水平上研究了与尺度变化和PDF集的选择有关的理论不确定性。通过直接比较完整的外壳过程与NWA的直接比较来研究该建模，在那里，$ z $ - 和$ w $ - 高的玻色子是在壳上进行的。此外，在实验性削减的动机上，我们还调查了在全部脱离壳预测中施加窗口削减的窗户块的影响。
NLO QCD corrections to the process $pp \rightarrow e^+ν_e μ^- \barν_μ τ^+τ^- b \bar{b}+X$ are presented with the full off-shell effects included. The calculation includes all resonant and non-resonant Feynman diagrams, photon and $Z$-gauge boson contributions, as well as interference effects, all incorporated at the matrix element level. Furthermore all heavy intermediate particles are described via Breit-Wigner propagators. Theoretical uncertainties related to the scale variation and choice of PDF sets were investigated at the integrated and differential level. The modelling is studied by a direct comparison of the full off-shell process to the NWA, where tops, $Z$- and $W$-gauge bosons are on-shell. Moreover, motivated by experimental cuts, we also investigate the impact of imposing a window cut around the mass of the $Z$-gauge boson on the full off-shell predictions.
