Precise Higgs-background predictions: merging NLO QCD and squared quark-loop corrections to four-lepton + 0,1 jet production
Precise Higgs-background predictions: merging NLO QCD and squared quark-loop corrections to four-lepton + 0,1 jet production
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DOI：
10.1007/jhep01(2014)046
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发表时间：
2013-09
影响因子：
5.4
通讯作者：
F. Cascioli;S. Hoeche;F. Krauss;P. Maierhofer;S. Pozzorini;F. Siegert
中科院分区：
文献类型：
--
作者：
F. Cascioli;S. Hoeche;F. Krauss;P. Maierhofer;S. Pozzorini;F. Siegert
我们提出了在全自动 Sherpa+ O pen Loops 框架内获得的大型强子对撞机中四轻子加喷流产生的精确预测。使用复质量方案始终包含离壳中间矢量玻色子和相关干扰。四轻子加上 0 和 1 射流最终状态以 NLO 精度进行描述，并且通过 gg→ 4ℓ、gg→ 4ℓ+ g、gq→ 4ℓ+ q 和→ 4ℓ+ g 通道中的平方夸克环 NNLO 贡献进一步提高了模拟精度。这些 NLO 和 NNLO 贡献与 S Herpa Parton 流星雨相匹配，并且使用 M eps@ N lo 技术一致地合并 0 和 1 射流最终状态。由于苏达科夫恢复，帕顿簇射为专有可观测值提供了改进的预测和不确定性估计。当使用喷射否决器或喷射箱来分离希格斯衰变、二玻色子产生和顶对产生产生的四轻子最终状态时，这一点很重要。给出了 0 和 1 喷射箱中 8 TeV 下 Atlas 和 C ms H→ WW* 分析的详细预测。评估重整化、因式分解和恢复尺度不确定性（也反映了喷射箱中未知的次主导苏达科夫对数），我们发现残余扰动不确定性小至几个百分点。
We present precise predictions for four-lepton plus jets production at the LHC obtained within the fully automated S herpa+ O pen L oops framework. Off-shell intermediate vector bosons and related interferences are consistently included using the complex-mass scheme. Four-lepton plus 0-and 1-jet final states are described at NLO accuracy, and the precision of the simulation is further increased by squared quark-loop NNLO contributions in the gg→ 4ℓ, gg→ 4ℓ+ g, gq→ 4ℓ+ q, and→ 4ℓ+ g channels. These NLO and NNLO contributions are matched to the S herpa parton shower, and the 0-and 1-jet final states are consistently merged using the M eps@ N lo technique. Thanks to Sudakov resummation, the parton shower provides improved predictions and uncertainty estimates for exclusive observables. This is important when jet vetoes or jet bins are used to separate four-lepton final states arising from Higgs decays, diboson production, and top-pair production. Detailed predictions are presented for the Atlas and C ms H→ WW* analyses at 8 TeV in the 0-and 1-jet bins. Assessing renormalisation-, factorisation-and resummationscale uncertainties, which reflect also unknown subleading Sudakov logarithms in jet bins, we find that residual perturbative uncertainties are as small as a few percent.