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圈积分及相空间积分计算系列讲座

29 October 2020 to 3 November 2020
腾讯会议
Asia/Shanghai timezone

Contribution List

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2. A Canonical Introduction to Feynman Integral Reduction
徐英轩 (Humboldt-Universitat zu Berlin)
29/10/2020, 01:00
In order to get high order scattering amplitudes, it is essential to calculate corresponding Feynman integrals. However, for multi-loop orders, there will be a huge number of Feynman integrals for a physical process. Thanks to the integration-by-parts (IBP) identities, we can reduce these integrals to a small set of integrals, i.e., master integrals. Here I give an introduction on IBP...
3. Usage of public IBP reduction packages: FIRE and Kira
Mr Mingming Long, Prof. Yang Zhang
29/10/2020, 02:00
FIRE 和 Kira 是目前最常使用的积分约化开源程序包。两者都主要基于 Laporta 算法，多核多节点并行，但又各有特色，FIRE 吸收了非交换代数构造递推关系的技巧，而 Kira 在大稀疏矩阵消元策略/代数运算底层并行上有专长。两者都可以和现代有限域计算方法相结合，提高计算速度。这次报告中，报告人将在线演示如何使用这两种软件。
13. Syzygy for Feynman integral reduction
Prof. Yang Zhang
29/10/2020, 03:00
19. Technique in Auxiliary Mass Flow
Prof. Zhao Li
29/10/2020, 04:00
20. IBP for gravitational wave physics
Prof. Mao Zeng
29/10/2020, 05:00
We describe the calculations of multi-loop scattering amplitudes in the context of binary black hole dynamics. The method of regions is used to expand the amplitudes in the limit of small $\hbar$. The expansion reduces the number of dimensionless kinematic variables from 3 to 1, which dramatically speeds up the subsequent IBP reduction, allowing us to calculate the 3-loop conservative dynamics...
21. Counting Master Integral: A Fascinating Problem
Jiuci Xu
29/10/2020, 06:00
4. Introduction to differential equation method for Feynman integral
徐小峰
30/10/2020, 01:00
Feynman integrals are one of the important ingredients to provide precise theoretical predictions for process at the LHC. Recently, there is significant progress in calculating Feynman integrals using differential equation method. In this lecture, I will introduce the canonical form of differential equations, the corresponding integrals called canonical basis, and I will discuss how to solve...
8. Analytic calculation--traditional methods for integrals
Dr Guo-Xing Wang
30/10/2020, 02:00
传统的积分方法在历史上起到了非常重要的作用。尽管目前微分方程的方法非常流行也非常强大，但是依然需要利用其它方法确定其边界条件。此外，在一些有效理论中出现的积分，微分方程的方法并不能很好的适用。此时，这些传统的方法便成为非常重要的处理手段。本次报告主要介绍三种传统的积分方法：parameterization，Mellin Barnes representation，Asymptotic expansions. 在报告中，报告人将分别介绍这些方法的基本概念和一些常用公式，并以一些简单的例子介绍如何在具体计算中使用这些积分方法。
14. Regularization and calculation of rapidity divergent Feynman integrals systematically
Dr Tong-Zhi Yang
30/10/2020, 03:00
22. Bootstrapping a two-loop four-point form factor
Prof. Gang Yang
30/10/2020, 04:00
We explain a recent computation of a two-loop four-point form factor in planar N=4 SYM, which belongs to the class of two-loop five-point scattering observables with one off-shell color-singlet leg. A new bootstrapping strategy is developed to obtain this result by starting with an ansatz expanded in terms of master integrals and then solving the master coefficients via various physical...
23. Efficient NLO computation for gg->HH/ZH with top quark mass dependence
Dr Guo-Xing Wang
30/10/2020, 05:00
Recently, we present a precise and efficient computation of the two-loop amplitudes entering gg->HH/ZH and present for the first time a calculation of the complete NLO corrections to the gg->ZH process. We use the method of small mass expansion to tackle the most challenging two-loop virtual amplitude, in which the top quark mass dependence is retained throughout the calculations. Our results...
24. Compton Scattering at Next-to-leading Order
Xiaoyuan Zhang
30/10/2020, 06:00
The analytic form for the total QED scattering cross section of an electron and a photon at order \alpha^3 is computed. This includes both the double-Compton scattering real-emission contribution as well as the virtual Compton scattering part. When combined with the recent analytic result for the pair-production cross section, the complete \alpha^3 cross section is now known. Both the...
0. Introduction to sector decomposition
李钊
31/10/2020, 01:00
简要介绍sector decomposition的基本原理，其方法的优势及局限性，介绍几个主流的工具。
9. Calculation of master integrals using difference equation method
Mr Zheng-Yang Li, Mr Zhi-Feng Liu
31/10/2020, 02:00
差分方程是计算主积分的一个重要方法。本次报告将介绍如何构建差分方程、求解差分方程，并给出科研中用到的具体例子。
15. Solving Master Integrals via Numerical Differential Equations
Xiao Liu
31/10/2020, 03:00
25. 圈积分的解析与数值计算若干方法与程序简介
Prof. Long-Bin Chen
31/10/2020, 04:00
本次报告将简单介绍圈积分的一些解析和数值计算方法，以及相关程序包的使用。例如微分方法方法来解析或数值计算圈积分，利用DiffExp 程序包来数值计算微分方程。 应用基于sector decomposition 方法的 FIESTA 程序包来对积分进行数值计算，以及利用GINAC来数值计算Goncharov Polylogarithms。
26. On the evaluation of two-loop electroweak box diagrams for e+ e- to HZ production
Qian Song
31/10/2020, 05:00
Precision studies of the Higgs boson at future e+e- colliders can help to shed light on fundamental questions related to electroweak symmetry breaking, baryogenesis, the hierarchy problem, and dark matter. The main production process, e+ e- to HZ, will need to be controlled with sub-percent precision, which requires the inclusion of next-to-next-to-leading order (NNLO) electroweak corrections....
27. AMF method 程序AMFlow
Dr Xiao Liu
31/10/2020, 06:00
这将是首个能够高精度计算任意圈积分、相空间积分的程序。
5. EFT perspectives on Feynman integrals/Matching QCD currents(operators) onto SCET
Prof. Xin-Qiang Li, Prof. Yu-Ming Wang
01/11/2020, 01:00
10. Applications of conformal symmetry in QCD
Dr Yao JI
01/11/2020, 02:00
Conformal symmetry provides significant simplifications to loop calculations in QCD for non-forward kinematics. In this talk, I will explain the relevant ideas detailing the procedures for applying conformal symmetry in QCD. I will review some recent results obtained through the conformal technique, which are immediately applicable to EIC physics, and meson decays.
16. Analyticity, renormalization, and evolution of the soft-quark function
Dr Xiang-Peng Wang
01/11/2020, 03:00
28. An introduction to the basics of SCET and method of regions
Prof. Jian Wang
01/11/2020, 04:00
Soft collinear effective theory is an effective theory of QCD in the infrared regions. It has been used widely in the study of infrared divergnces of scattering amplitudes and of resummation of large logarithms in cross sectons. It helps one to obtain much information about the higher order corrections. The method of regions is another useful tool to calculate loop integrals up to certain...
29. Resummation of Super-Leading Logarithms
Prof. Ding-Yu Shao
01/11/2020, 05:00
Jet cross sections at high-energy colliders exhibit intricate patterns of logarithmically enhanced higher-order corrections. In particular, so-called non-global logarithms emerge from soft radiation emitted off energetic partons inside jets. While this is a single-logarithmic effect at lepton colliders, at hadron colliders phase factors in the amplitudes lead to double-logarithmic corrections...
30. SCET factorization for the radiative leptonic B-meson decays
Dr Yan-Bing Wei
01/11/2020, 06:00
The radiative leptonic B-meson decays are extremely important to the study of the exclusive B-meson decays. I will concentrate on the factorization properties of the radiative leptonic B decay with an energetic photon in the final states. Employing the method of regions, we can derive the factorization formula of the decay form factors at the leading power. The factorization formula could be...
6. Phase space integration-overview/Slicing method and soft function at NNLO
Prof. Jian Wang, Prof. Xiao-Hui Liu
02/11/2020, 01:00
11. Calculation of phase-space integration of sufficient inclusive processes
Peng Zhang
02/11/2020, 02:00
In this talk, I will introduce a systematic method (inverse unitarity+differential equations+auxiliary mass flow) to calculate phase-space integration for sufficient inclusive processes. With this method, we can get numerical results with high precision efficiently.
17. 高精度现象学和减除法
Dr Xuan Chen
02/11/2020, 03:00
31. Introduction to parton shower
Dr Hai-Tao Li
02/11/2020, 04:00
Monte-Carlo event generators have been widely used to simulate the processes in high-energy physics. Parton shower plays a central role in Monte-Carlo event generators which provides a reliable tool to perform the leading logarithms resummation. Precision prediction from parton shower requires more theory developments such as proof of NLL resummation and NLO shower framework. Beyond the...
32. Light-ray OPE in QCD
Hao Chen
02/11/2020, 05:00
Light-ray operators play an important role in various areas of physics and, in particular, are natural language for an interesting class of observables in collider physics, including energy-energy correlator (EEC). Similar to operator product expansion (OPE) of local operators, OPE of light-ray operators governs the collinear behavior of these observables. In this talk, I will first briefly...
33. The pion-photon transition form factor at two loops in QCD
Dr Yao Ji
02/11/2020, 06:00
In this talk, I will report on our recent fully analytic calculation of the leading-power contribution to the photon-pion transition form factor at two loops in QCD. The applied techniques rely on hard-collinear factorization, together with modern multi-loop methods. I will focus both on the technical details, such as the treatment of evanescent operators, and the phenomenological...
7. pfd: a Singular Library to Simplify IBP Reduction Coefficients
Mr Zihao Wu
03/11/2020, 01:00
12. Introduction to FDC project
Prof. Bin Gong
03/11/2020, 02:00
18. Introduction to FORM
Prof. Zhao Li
03/11/2020, 03:00
34. An introduction to the computer algebra system Singular
Prof. Yang Zhang
03/11/2020, 04:00
35. FiniteFlow程序的物理和使用
Chuan-Qi He, Xin Guan
03/11/2020, 05:00
36. Julia编程语言介绍
Prof. Zhao Li
03/11/2020, 06:00
1. TBA
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