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费曼积分计算助力高精度粒子物理时代

中国科学:物理学、力学、天文学 2023年第10期53卷 52-64页

作者：刘志峰马滟青北京大学物理学院北京100871 北京大学高能物理中心北京100871

微扰量子场论计算对于精确检验粒子物理标准模型及探索新物理起着至关重要的作用.使用微扰论计算物理过程时,多圈费曼积分的计算是其瓶颈所在.本文从费曼积分的计算方法到其唯象学应用介绍了这一研究方向的现状与未来发展趋势.随着未来... 详细信息

微扰量子场论计算对于精确检验粒子物理标准模型及探索新物理起着至关重要的作用.使用微扰论计算物理过程时,多圈费曼积分的计算是其瓶颈所在.本文从费曼积分的计算方法到其唯象学应用介绍了这一研究方向的现状与未来发展趋势.随着未来的粒子对撞机的规划与建设,费曼积分的研究将继续扮演重要角色,推动粒子物理全面迈入高精度时代.

关键词：微扰量子场论费曼积分对撞机物理

Theory for quarkonium:from NRQCD factorization to soft gluon factorization

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Chinese Physics C 2021年第1期45卷 196-207页

作者：陈安平马滟青 School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for High Energy physics Peking UniversityBeijing 100871China College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China Collaborative Innovation Center of Quantum Matter.Beijing 100871 China

We demonstrate that the recently proposed soft gluon factorization(SGF)is equivalent to the nonrelativistic QCD(NRQCD)factorization for heavy quarkonium production or decay,which means that,for any given process,these two factorization theories are either both valid or both violated.We use two methods to arrive at this conclusion.In the first method,we apply the two factorization theories to the physical process J/ψ→e^+e^-.Our explicit calculation shows that both SGF and NRQCD can correctly reproduce the low energy physics of full QCD,and the two factorizations are thus equivalent.In the second method,by using equations of motion,we successfully deduce SGF from NRQCD effective field theory.By identifying SGF with NRQCD factorization,we establish relations between the two factorization theories and prove the generalized Gremm-Kapustin relation as a byproduct.Compared with the NRQCD factorization,the advantage of SGF is that it resums the series of relativistic corrections originating from kinematic effects to all powers,yielding better convergence of the relativistic expansion.

关键词： factorization quarkonium nonrelativistic QCD soft gluon

Calculation of Feynman loop integration and phase-space integration via auxiliary mass flow

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Chinese Physics C 2021年第1期45卷 162-174页

作者：刘霄马滟青陶伟张鹏 School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for High Energy Physics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We extend the auxiliary-mass-flow(AMF) method originally developed for Feynman loop integration to calculate integrals which also involve phase-space integration.The flow of the auxiliary mass from the boundary(∞) to the physical point(0+) is obtained by numerically solving differential equations with respective to the auxiliary mass.For problems with two or more kinematical invariants,the AMF method can be combined with the traditional differential-equation method,providing systematic boundary conditions and a highly nontrivial self-consistency check.The method is described in detail using a pedagogical example of e+e-→γ*→tt+X at NNLO.We show that the AMF method can systematically and efficiently calculate integrals to high precision.

关键词： phase-space integration perturbation theory multi-loop

NLO effects for Ω_(QQQ) baryons in QCD Sum Rules

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Chinese Physics C 2021年第9期45卷 44-54页

作者：吴仁华左羽生孟策马滟青赵光达 School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for High Energy Physics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We study the triply heavy baryonsΩ_(QQQ)(Q=c,b)in the QCD sum rules by performing the first calculation of the next-to-leading order(NLO)contribution to the perturbative QCD part of the correlation functions.Compared with the leading order(LO)result,the NLO contribution is found to be very important to theΩ_(QQQ).This is because the NLO not only results in a large correction but also reduces the parameter dependence,making the Borel platform more distinct,especially for the Q_(bbb)in the MS scheme,where the platform appears only at NLO but not at LO.Particularly,owing to the inclusion of the NLO contribution,the renormalization schemes(MS and On-Shell)dependence and the scale dependence are significantly reduced.Consequently,after including the NLO contribution to the perturbative part in the QCD sum rules,the masses are estimated to be 4.53_)0.11)^(+0.26) GeV forΩ_(ccc) and14.27_(-0.32)^(+0.33) GeV forΩ_(bbb),where the results are obtained atμ=M_(B) with errors including those from the variation of the renormalization scaleμin the range(0.8-1.2)M_(B).A careful study of theμdependence in a wider range is further performed,which shows that the LO results are very sensitive to the choice ofμwhereas the NLO results are considerably better.In addition to theμ=M_(B) result,a more stable value,(4.75-4.80)GeV,for theΩ_(ccc) mass is found in the range ofμ=(1.2-2.0)M_(B),which should be viewed as a more relevant prediction in our NLO approach because of μ dependence.

关键词： baryon heavy quark QCD sum rules NLO correction

Complete reduction of integrals in two-loop five-light-parton scattering amplitudes

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Chinese Physics C 2020年第9期44卷 62-68页

作者：关鑫刘霄马滟青 School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Center for High Energy Physics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

We reduce all the most complicated Feynman integrals in two-loop five-light-parton scattering amplitudes to basic master integrals,while other integrals can be reduced even easier.Our results are expressed as systems of linear relations in the block-triangular form,very efficient for numerical calculations.Our results are crucial for complete next-to-next-to-leading order quantum chromodynamics calculations for three-jet,photon,and/or hadron production at hadron colliders.To determine the block-triangular relations,we develop an efficient and general method,which may provide a practical solution to the bottleneck problem of reducing multiloop multiscale integrals.

关键词： Feynman integrals reduction five-light-parton scattering

碳点/聚氨酯荧光泡沫复合材料的制备及性能研究

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化工新型材料 2024年

作者：白静静仝锡杰马滟宇常雁峰李振中太原工业学院材料工程系

以碳点（CDs）水热合成产物为发泡剂，经原位发泡制备碳点/聚氨酯荧光泡沫（CDs/PUF）复合材料。通过对泡沫微观结构表征及宏观性能的测试分析，研究不同含量CDs溶液对发泡过程、泡沫结构及性能的影响。结果表明：CDs与聚氨酯泡沫基体... 详细信息

以碳点（CDs）水热合成产物为发泡剂，经原位发泡制备碳点/聚氨酯荧光泡沫（CDs/PUF）复合材料。通过对泡沫微观结构表征及宏观性能的测试分析，研究不同含量CDs溶液对发泡过程、泡沫结构及性能的影响。结果表明：CDs与聚氨酯泡沫基体通过化学键结合，扰乱了大分子链的有序排列，加速了发泡过程中的凝胶反应，同时CDs作为异相成核剂，增加了单位体积内的泡孔数量，孔径分布均匀，泡孔结构完整性增强，孔壁厚度增加，开孔率降低；复合材料压缩强度最大提高113%，耐热性能得到改善。CDs在复合材料中分散良好，荧光特性得以很好地保留，随着CDs含量增加，复合材料荧光强度增强，绝对荧光量子产率最高达19.92%。

关键词：聚氨酯泡沫碳点复合材料荧光

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高铁区位对中国异地投资的影响与异质性评价

地理科学 2024年第3期44卷 400-410页

作者：焦敬娟马王钰青王伟北京交通大学经济管理学院北京100044 中国铁路经济规划研究院有限公司经济与管理研究所北京100038 青岛大学旅游与地理科学学院山东青岛266071

作为一种特殊的跨区域重大基础设施,高速铁路(下文简称为“高铁”)开通减少沿线企业面临的要素约束,降低企业间的信息不对称和代理成本,促进沿线地区资本流动,影响城市间的异地投资。依托2008-2017年中国上市公司新建投资决策数据,以高... 详细信息

作为一种特殊的跨区域重大基础设施,高速铁路(下文简称为“高铁”)开通减少沿线企业面临的要素约束,降低企业间的信息不对称和代理成本,促进沿线地区资本流动,影响城市间的异地投资。依托2008-2017年中国上市公司新建投资决策数据,以高铁所引致的连通性和可达性等区位条件变化为切入,分析和评价高铁对异地投资的影响及其空间异质性。研究发现:①东部地区连通性提升更快,西部地区可达性改善更显著;巨特大城市与中小城市的可达性和连通性的绝对差距不断拉大。②异地投资主要流向东部地区和巨特大城市,但地区差异呈缩小态势。③高铁区位对异地投资有显著正向影响,并且可达性的影响程度大于连通性的影响。④高铁区位对不同地区、不同规模城市异地投资的影响呈现差异性,连通性促进资金向东部地区和巨特大城市流动,可达性则能够显著提升西部地区及小城市对异地投资的吸引。

关键词：高铁区位重大基础设施连通性异地投资空间异质性

球磨和液相烧结制备W-Ni-Fe合金的组织和力学性能

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稀有金属材料与工程 2024年第5期53卷 1229-1235页

作者：王姿曈董帝熊宁徐嘉伟董智马宗青天津大学材料科学与工程学院天津300072 安泰天龙钨钼科技有限公司北京100094 海天塑机集团有限公司浙江宁波315801

为了制备出优异、经济友好的钨重合金,在1450~1510℃的烧结温度范围内,通过球磨和液相烧结制备了93W-4.6Ni-2.4Fe(质量分数)合金。进一步研究了试样的微观结构和断裂模式。结果表明,在不同烧结温度下,烧结的试样表现出相似的两相显微结... 详细信息

为了制备出优异、经济友好的钨重合金,在1450~1510℃的烧结温度范围内,通过球磨和液相烧结制备了93W-4.6Ni-2.4Fe(质量分数)合金。进一步研究了试样的微观结构和断裂模式。结果表明,在不同烧结温度下,烧结的试样表现出相似的两相显微结构和韧性断裂模式。随着烧结温度的升高,钨颗粒尺寸也逐渐增大。当烧结温度达到或超过1480℃时,合金相对密度达到99.0%以上。1480℃烧结时可获得具有最佳抗拉伸强度(940 MPa)和延伸率(32.6%)组合的试样。在1480℃下烧结的试样具有优异的延展性,这与γ相的网络结构、韧窝的均匀分布以及两相的协同作用有关。试样的高强度归因于细化的钨颗粒尺寸和球形的钨颗粒。

关键词：钨重合金球磨液相烧结力学性能

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碳点/聚氨酯泡沫复合材料的制备及性能研究

化工新型材料 2024年第7期52卷 63-68页

作者：白静静仝锡杰马滟宇常雁峰李振中太原工业学院材料工程系太原030008

以碳点(CDs)水热合成产物为发泡剂,经原位发泡制备碳点/聚氨酯泡沫(CDs/PUF)复合材料。通过对泡沫微观结构表征及宏观性能的测试分析,研究不同含量CDs溶液对发泡过程、泡沫结构及性能的影响。结果表明:CDs与聚氨酯泡沫基体通过化学键结... 详细信息

以碳点(CDs)水热合成产物为发泡剂,经原位发泡制备碳点/聚氨酯泡沫(CDs/PUF)复合材料。通过对泡沫微观结构表征及宏观性能的测试分析,研究不同含量CDs溶液对发泡过程、泡沫结构及性能的影响。结果表明:CDs与聚氨酯泡沫基体通过化学键结合,扰乱了大分子链的有序排列,加速了发泡过程中的凝胶反应,同时CDs作为异相成核剂,增加了单位体积内的泡孔数量,孔径分布均匀,泡孔结构完整性增强,孔壁厚度增加,开孔率降低;复合材料压缩强度最大提高113%,耐热性能得到改善。CDs在复合材料中分散良好,荧光特性得以很好地保留,随着CDs含量增加,复合材料荧光强度增强,绝对荧光量子产率最高达19.92%。

关键词：聚氨酯泡沫碳点复合材料荧光