论文标题
SMEFT的量子纠缠和顶部自旋相关性在较高阶
Quantum entanglement and top spin correlations in SMEFT at higher orders
论文作者
论文摘要
在标准模型有效场理论的背景下，我们介绍了最高自旋极化，$ t \ bar t $旋转相关性和$ t \ bar t $旋转纠缠，这超出了领先顺序QCD的精度。确定了输入$ t \ b t $生产的一组独立尺寸-6操作员，它们对所有顶级旋转观测值的影响均以$ c/λ^2 $的线性和二次订单提取。通过比较LO和NLO的结果，我们注意到，较高订单的包含虽然没有显着更改图片，但通常相当于明显的数值差异，而这些数字差异并未被LO规模变化完全捕获。我们还发现，与SM的预期偏差具有复杂的相空间结构，并且主要出现在大型$ P_T $上。因此，我们主张在$ t \ bar t $相位空间中差异化或双分化的旋转观测值。我们还通过解决平面方向的问题来展示当前和未来的顶级旋转测量方法将如何改善全球拟合到顶级LHC数据。
We present the first analysis of top spin polarizations, $t \bar t$ spin correlations, and $t \bar t$ spin entanglement at the LHC in the context of the Standard Model Effective Field Theory, that goes beyond Leading Order QCD accuracy. The complete set of independent dimension-6 operators entering $t \bar t$ production is identified, and their effects on all top spin observables are extracted at linear and quadratic order in $c/Λ^2$. By comparing results at LO and NLO, we note that the inclusion of higher orders, while not dramatically changing the picture, often amounts to notable numerical differences, that are not fully captured by LO scale variation. We also find that the expected deviations from the SM have an intricate phase space structure, and show up predominantly at large top $p_T$. For this reason, we advocate for the measurement of spin observables differentially or doubly-differentially in the $t \bar t$ phase-space. We show how the inclusion of present and future top spin measurements will improve global fits to top LHC data, by also addressing the issue of flat directions.
