共振感知的电弱Sudakov重加权用于多喷注合并预测
Resonance-aware electroweak Sudakov reweighting for multijet-merged predictions
- Jožef Stefan Institute（约瑟夫·斯特凡研究所）
- University of Ljubljana（卢布尔雅那大学）
- Lund University（隆德大学）
- INFN（意大利国家核物理研究所）
- Uppsala University（乌普萨拉大学）
- ELTE Eötvös Loránd University（厄特沃什·罗兰大学）
- Università degli Studi di Milano（米兰大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出共振感知的电弱Sudakov重加权方法，用于多喷注合并模拟，考虑自旋关联并移除光子对数，在Z+喷注和W+W−产生中验证其高能抑制效应，提供实用的虚弱Sudakov近似。
AI中文摘要：
我们在MadGraph5_aMC@NLO中提出了一种共振感知的电弱Sudakov对数重加权的扩展，用于NLO QCD匹配和FxFx多喷注合并的事件样本。该方法识别每个事件背后的硬产生过程，并在考虑不稳定粒子与其衰变产物之间的自旋关联的同时，评估其电弱Sudakov修正。从虚权重中移除光子对数，以避免与QED簇射演化重叠。我们在FxFx合并的$Z$+喷注产生和全轻子$W^+W^-$产生中验证了该方法。重加权在高能尾部产生预期的增长性弱抑制，并且对聚类和合并参数的变化保持稳定。在$W^+W^-$产生中，密度矩阵和自旋求和方案在所研究的观测量上统计相容，表明该通道中Sudakov修正仅具有较小的额外螺旋度依赖性。该方法为匹配和合并模拟提供了一种实用的虚弱Sudakov近似，但并不构成精确的NLO电弱计算。
英文摘要：
We present a resonance-aware extension of electroweak Sudakov-logarithm reweighting in MadGraph5_aMC@NLO for NLO QCD-matched and FxFx multijet-merged event samples. The method identifies the hard production process underlying each event and evaluates its electroweak Sudakov correction while accounting for the spin correlations between unstable particles and their decay products. Photonic logarithms are removed from the virtual weight to avoid overlap with QED shower evolution. We validate the method in FxFx-merged $Z$+jets production and fully leptonic $W^+W^-$ production. The reweighting yields the expected growing weak suppression in high-energy tails and is stable under variations of the clustering and merging parameters. In $W^+W^-$ production, the density-matrix and spin-summed prescriptions are statistically compatible for the observables studied, indicating only a small additional helicity dependence of the Sudakov correction in this channel. The method provides a practical virtual weak-Sudakov approximation for matched and merged simulations, but does not constitute an exact NLO electroweak calculation.
