We calculate the angular distribution spectra between beauty ($B$) and anti-beauty ($\bar B$) mesons in proton-proton collisions in the leading order approximation of the parton Reggeization approach consistently merged with the next-to-leading order corrections from the emission of additional hard gluon. To describe b-quark hadronization we use the universal scale-depended parton-to-meson fragmentation functions extracted from the world $e^+e^-$ annihilation data. We have obtained good agreement between our predictions and data from the CMS Collaboration at the energy $\sqrt{S}=7$ TeV for $B \bar B$ angular correlations within uncertainties and without free parameters. Predictions for analogous correlation observables at $\sqrt{S}=13$ TeV are provided.
In the article, we study single and pair $J/ψ$ hadroproduction in the Improved Color Evaporation Model via the Parton Reggeization Approach. The last one is based on $k_T$-factorization of hard processes in multi-Regge kinematics, the Kimber-Martin-Ryskin-Watt model for unintegrated parton distribution functions, and the effective field theory of Reggezied gluons and quarks, suggested by L.N. Lipatov. We compare contributions from the single and double parton scattering mechanisms in the pair $J/ψ$ production. The numerical calculations are realized using the Monte-Carlo event generator KaTie.
DbarD and DD pair production at the LHCb in the parton Reggeization approach
本文采用部分子Regge化方法,在LHC上研究了质子-质子碰撞中包含的DbarD和DD对的产生,并给出了c-夸克到D-介子和胶子到D-介子跃迁的普遍尺度相关碎裂函数。本文描述了DbarD和DD在方位角上的分布,以及LHCb合作组在没有自由参数的情况下在大快度2 < y < 4区域测量的横动量、快度距离和不变质量。我们对过程RR-gg和RR-cbarc使用了Reggeized振幅,它们是根据L. N. Reggeized部分子的Lipatov有效理论和以Martin-Stirling-Thorne-Watt共线部分子分布为输入的质子中未积分胶子分布函数的Kimber-Martin-Ryskin模型。
We study large-$p_T$ three-photon production at the LHC at the center-of-mass energy $\sqrt{s}=8$ TeV. We use the LO approximation of the parton Reggeization approach consistently merged with the real NLO corrections. For numerical calculations use the parton-level generator KaTie and modified KMR-type unintegrated parton distribution functions. We find good agreement between our predictions and data with the same accuracy as in the NNLO calculations based on the collinear parton model of QCD. At higher energies ($\sqrt{s}=13$ and 27 TeV) parton Reggeization approach predicts larger cross sect…
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 studie…
Accelerating multijet-merged event generation with neural network matrix element surrogates
Institut für Kern und Teilchenphysik, TU Dresden(德累斯顿工业大学核与粒子物理研究所);Institut für Theoretische Physik, Georg-August-Universität Göttingen(哥廷根大学理论物理研究所);Campus-Institut Data Science, Georg-August-Universität Göttingen(哥廷根大学校园数据科学研究所)
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。
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。
We consider the production of a pair of $Z$ bosons at the LHC and study the inclusion of EW corrections in theoretical predictions at fixed order and based on multijet-merged parton-shower simulations. To this end we present exact NLO EW results for $pp\to e^+e^-μ^+μ^-$, and, for the first time, for $pp\to e^+e^-μ^+μ^-j$, and compare them to the EW virtual and NLL Sudakov approximation. We then match the exact NLO EW result to the resummed Sudakov logarithms to achieve an improved NLO EW + NLL $\text{EW}_\text{sud}^\text{exp}$ result. Further, we discuss the inclusion of the above EW correctio…