First, we present a combined analysis of ${\rm p}{\rm p} \to μ^+ ν_μ{\rm e}^- \bar ν_{\rm e}$ and ${\rm p}{\rm p} \to μ^+ ν_μ{\rm e}^- \bar ν_{\rm e} {\rm j}$ at next-to-leading order, including both QCD and electroweak corrections. Second, we provide all-order predictions for ${\rm p}{\rm p} \to μ^+ ν_μ{\rm e}^- \bar ν_{\rm p}+\mathrm{jets}$ using merged parton-shower simulations that also include approximate EW effects. A fully inclusive sample for WW production is compared to the fixed-order computations for exclusive zero- and one-jet selections. The various higher-order effects are studied in detail at the level of cross sections and differential distributions for realistic experimental set-ups. Our study confirms that merged predictions are significantly more stable than the fixed-order ones in particular regarding ratios between the two processes.
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)
The W boson production cross section at the LHC through O(alpha_s^2)
我们计算了对全微分截面pp \to W X \to l νX的O(α_s^2)QCD修正,保留了自旋关联的所有影响。这些修正的知识使得有可能计算高精度的W玻色子的生产率和接受在大型强子对撞机,受到现实削减的轻子和丢失的能量分布。对于某些选择的削减,我们发现大的修正时,从下一个到领先的顺序(NLO)到下一个到下一个到领先的顺序(NNLO)在微扰理论。这些修正是显着大于部分子簇射事件发生器合并NLO计算得到的。我们的计算可以用来评估和显着减少QCD的不确定性在许多研究的$W$玻色子生产计划在大型强子对撞机。
Phase space veto method for next-to-leading order event generators in hadronic collisions
利用一个否决权来组织次主导阶QCD的计算,该否决权使得虚发射图和实发射图之间相互抵消,这种方法被应用于强子碰撞。该方法采用相空间切片与切片参数动态确定的事件。它允许产生未加权的事件,并能与部分子簇射一致地合并。最终产品对于最终用户来说更直观,因为它是概率性的,并且可以很容易地与通用淋浴和强子化程序接口,以获得适合于实验分析的完整事件描述。作为一个例子,事件发生器的过程pp --> Z + X在NLO和接口一致的PYTHIA淋浴和强子化包。