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Resolving the Bethe–Salpeter Kernel

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Chinese Physics Letters 2021年第7期38卷 17-22页

作者： Si-Xue Qin craig d.roberts department of Physics Chongqing UniversityChongqing 401331China School of Physics Nanjing UniversityNanjing 210093China Institute for Nonperturbative Physics Nanjing UniversityNanjing 210093China

A novel method for constructing a kernel for the meson bound-state problem is *** produces a closed form that is symmetry-consistent(discrete and continuous)with the gap equation defined by any admissible gluon-quark vertex,Γ.Applicable even when the diagrammatic content ofΓis unknown,the scheme can foster new synergies between continuum and lattice approaches to strong *** framework is illustrated by showing that the presence of a dressed-quark anomalous magnetic moment inΓ,an emergent feature of strong interactions,can remedy many defects of widely used meson bound-state kernels,including the mass splittings between vector and axial-vector mesons and the level ordering of pseudoscalar and vector meson radial excitations.

关键词： meson quark admissible

Pauli Radius of the Proton

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Chinese Physics Letters 2021年第12期38卷 1-6页

作者： Zhu-Fang Cui daniele Binosi craig d.roberts Sebastian M.Schmidt School of Physics Nanjing UniversityNanjing 210093China Institute for Nonperturbative Physics Nanjing UniversityNanjing 210093China European Centre for Theoretical Studies in Nuclear Physics and Related Areas Villa TambosiStrada delle Tabarelle 286I-38123 Villazzano(TN)Italy Helmholtz-Zentrum dresden-Rossendorf Dresden D-01314Germany RWTH Aachen University Ⅲ.Physikalisches Institut BAachen D-52074Germany

Using a procedure based on interpolation via continued fractions supplemented by statistical sampling,we analyze proton magnetic form factor data obtained via electron+proton scattering on Q^(2)∈[0.027,0.55]GeV^(2)with the goal of determining the proton magnetic *** approach avoids assumptions about the function form used for data interpolation and ensuing extrapolation onto Q^(2)■0 for extraction of the form factor *** this way,we find r_(M)=0.817(27)*** the difference between proton electric and magnetic radii calculated in this way,extant data are seen to be compatible with the possibility that the slopes of the proton dirac and Pauli form factors,F1,2(Q^(2)),are not truly independent observables;to wit,the difference F_(1)’(0)-F_(2)’(0)/κp=[1+Kp]/[4 m_(p)^(2)],viz.,the proton Foldy term.

关键词： interpolation Pauli continued

Hadron and light nucleus radii from electron scattering

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Chinese Physics C 2022年第12期46卷 1-15页

作者： Zhu-Fang Cui daniele Binosi craig d.roberts Sebastian M.Schmidt School of Physics Nanjing UniversityNanjing 210093China Institute for Nonperturbative Physics Nanjing UniversityNanjing 210093China European Centre for Theoretical Studies in Nuclear Physics and Related Areas Villa Tambosi Strada delle Tabarelle 286I-38123 Villazzano(TN)Italy Helmholtz-Zentrum dresden-Rossendorf Dresden D-01314Germany RWTH Aachen University Ⅲ.Physikalisches Institut BAachen D-52074Germany

Conceptually,radii are amongst the simplest Poincaré-invariant properties that can be associated with hadrons and light *** values of these quantities are necessary so that one may judge the character of putative solutions to the strong interaction problem within the Standard ***,limiting their ability to serve in this role,recent measurements and new analyses of older data have revealed uncertainties and imprecisions in the radii of the proton,pion,kaon,and *** the context of radius measurement using electron+hadron elastic scattering,the past decade has shown that reliable extraction requires minimisation of bias associated with practitioner-dependent choices of data fitting *** answers to that challenge have been offered;and this perspective describes the statistical Schlessinger point method(SPM),in unifying applications to proton,pion,kaon,and deuteron *** in analytic function theory,independent of assumptions about underlying dynamics,free from practitioner-induced bias,and applicable in the same form to diverse systems and observables,the SPM returns an objective expression of the information contained in any data under *** robust nature and versatility make it suitable for use in many branches of experiment and theory.

关键词： elastic electromagnetic form factors lepton scattering from hadrons and light nuclei emergence of mass muonic atoms proton Nambu-Goldstone modes-pion and kaon deuteron strong interactions in the standard model of particle physics

All-Orders Evolution of Parton distributions:Principle,Practice,and Predictions

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Chinese Physics Letters 2023年第9期40卷 24-31页

作者：尹佩林徐胤禛崔钫 craig d.roberts José Rodríguez-Quintero College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China dpto.Ciencias Integradas Centro de Estudios Avanzados en Fis.Mat.y Comp.Fac.Ciencias ExperimentalesUniversidad de HuelvaHuelva 21071Spainl dpto.Sistemas Físicos Químicos y NaturalesUniv.Pablo de OlavideE-41013 SevillaSpain School of Physics Nanjing UniversityNanjing 210093China Institute for Nonperturbative Physics Nanjing UniversityNanjing 210093China

Parton distribution functions(PdFs)are defining expressions of hadron *** the role of effective charges in quantum chromodynamics,an algebraic scheme is described which,given any hadron’s valence parton PdFs at the hadron scale,delivers predictions for all its PdFs(unpolarized and polarized)at any higher *** scheme delivers results that are largely independent of both the value of the hadron scale and the pointwise form of the charge;and,inter alia,enables derivation of a model-independent identity that relates the strength of the proton’s gluon helicity PdF,ΔG_(p)ζ,to that of the analogous singlet polarized quark PdF and valence quark momentum *** available data fits and theory predictions,the identity yieldsΔG_(p)(ζC=√3 GeV)=1.48(10).It furthermore entails that the measurable quark helicity contribution to the proton spin is a_(op)^(ζC)=0.32(3),thereby reconciling contemporary experiment and theory.

关键词： structure theory quark

Valence Quark Ratio in the Proton

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Chinese Physics Letters 2022年第4期39卷 1-6页

作者： Zhu-Fang Cui Fei Gao daniele Binosi Lei Chang craig d.roberts Sebastian M.Schmidt School of Physics Nanjing UniversityNanjing 210093China Institute for Nonperturbative Physics Nanjing UniversityNanjing 210093China Centre for High Energy Physics Peking UniversityBeijing 100871China European Centre for Theoretical Studies in Nuclear Physics and Related Areas Villa TambosiStrada delle Tabarelle 286I-38123 Villazzano(TN)Italy School of Physics Nankai UniversityTianjin 300071China Helmholtz-Zentrum dresden-Rossendorf Dresden D-01314Germany RWTH Aachen University III.Physikalisches Institut BAachen D-52074Germany

Beginning with precise data on the ratio of structure functions in deep inelastic scattering(dIS)from ^3He and ^3H,collected on the domain 0.19≤xB≤0.83,where xBis the Bjorken scaling variable,we employ a robust method for extrapolating such data to arrive at a model-independent result for the xB=1 value of the ratio of neutron and proton structure *** this with information obtained in analyses of dIS from nuclei,corrected for target-structure dependence,we arrive at a prediction for the proton valence-quark ratio:d_(v)/u_(v)|_(xB→1)=0.230(57).Requiring consistency with this result presents a challenge to many descriptions of proton structure.

关键词： structure functions precise

Collective Perspective on Advances in dyson–Schwinger Equation QCd

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Communications in Theoretical Physics 2012年第7期58卷 79-134页

作者： Adnan Bashir Ian C.Clet Bruno El-Bennich craig d.roberts Peter C.Tandy Instituto de Física y Matemticas Universidad Michoacana de San Nicols de Hidalgo Edificio C-3Ciudad UniversitariaMoreliaMichoacn 58040Mxico Physics division Argonne National Laboratory ArgonneIllinois 60439USA Center for Nuclear Research Department of PhysicsKent State UniversityKent OH 44242USA CSSM and CoEPP School of Chemistry and Physics University of AdelaideAdelaide SA 5005Australia Laboratorio de Física Teórica e Computao Científica Universidade Cruzeiro do Sul01506-000 So PauloSPBrazil Instituto de Física Torica Universidade Estadual Paulista01140-070 So PauloSPBrazil department of Physics Center for High Energy Physics and State Key Laboratory of Nuclear Physics and TechnologyPeking University Institut für Kernphysik Forschungszentrum JülichD-52425 JülichGermany department of Physics Illinois Institute of TechnologyChicagoIllinois 60616-3793USA

We survey contemporary studies of hadrons and strongly interacting quarks using QCd's dyson-Schwinger equations, addressing the following aspects: confinement and dynamical chiral symmetry breaking; the hadron spectrum; hadron elastic and transition form factors, from small-to large-Q2; parton distribution functions; the physics of hadrons containing one or more heavy quarks; and properties of the quark gluon plasma.

关键词： confinement dynamical chiral symmetry breaking dyson-Schwinger equations hadron spectrum hadron elastic and transition form factors heavy mesons in-hadron condensates parton distribution functions quark gluon plasma UA(1)-problem

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丈量宇宙最强力

环球科学 2024年第11期 24-31页

作者：斯坦利·J.布罗德斯基亚历山大·德尔克雷格·d.罗伯茨李新鹏(翻译) 崔钫(审校) 美国斯坦福大学SLAC国家加速器实验室美国弗吉尼亚州纽波特纽斯市托马斯·杰斐逊(Thomas Jefferson)国家加速器设施南京大学物理学院

宇宙中最强之力,也恰巧被称作强力。我们从来没有亲眼见证过它强大的力量,因为这种力仅作用在亚原子尺度。在这一尺度下,强力会将质子和中子中的夸克束缚在一起,然后将这些核子结合成原子核。宇宙中迄今为止已知的四种基本力是引力、电... 详细信息

宇宙中最强之力,也恰巧被称作强力。我们从来没有亲眼见证过它强大的力量,因为这种力仅作用在亚原子尺度。在这一尺度下,强力会将质子和中子中的夸克束缚在一起,然后将这些核子结合成原子核。宇宙中迄今为止已知的四种基本力是引力、电磁力、弱力和强力,其中强力是最强的——它是引力的100万亿万亿万亿(1038)倍。但与此同时,它也是我们现在所知最少的基本力。

关键词：亚原子引力夸克电磁力弱力原子核强力宇宙

Study of the wall adhesive tensile contact of moist iron ore bulk solids

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Particuology 2020年第3期18卷 67-75页

作者： Tao Fang Wei Chen Jens Plinke craig Wheeler Alan roberts School of Civil Engineering East China Jiaotong UniversityNanchang 330013China School of Engineering The University of NewcastleCallaghan 2308Australia

The adhesive tensile stress between moist bulk iron ore solids and wall surfaces are critical to control and avoid blockage in large throughput material handling *** this study,an experimental system was designed to investigate the adhesive tensile contact between a range of iron ore materials and wall lining *** contact mechanism between the material specimen and the wall surface was initially *** experimental results indicated that the adhesive tensile stress is dependent on both the moisture content and the applied major consolidation stress,with the former exhibiting more significant contribution to increasing the magnitude of *** surface roughness of the wall showed a negligible effect in determining the adhesive tensile ***,the iron ore sample with a higher fines content was observed to be able to achieve a higher adhesive tensile stress compared to the coarse ***,the insights resulting from the study demonstrated practical applicability through measures such as blending and/or beneficiation,which reduce the adhesive tensile stress and minimise blockages.

关键词： Wet sticky material Adhesive tensile stress Wall linings Liquid bridge force Capillary stress Soil texture

Exploring the light-quark interaction

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Chinese Physics C 2009年第12期33卷 1189-1196页

作者：常雷 Ian C. CLOЁT Bruno El-BENNICH Thomas KLHN craig d. roberts Institute of Applied Physics and Computational Mathematics department of Physics University of Washington Seattle WA 98195 USA Physics division Argonne National Laboratory Argonne Illinois 60439 USA department of Physics Peking University

Two basic motivations for an upgraded JLab facility are the needs： to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking （dCSB）; and to understand nucleon structure and spectroscopy in terms of QCd＇s elementary degrees of freedom. during the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a dyson- Schwinger equation perspective on this effort with numerous illustrations, amongst them： an interpretation of string^breaking; a symmetry-preserving truncation for mesons; the nucleon＇s strangeness σ-term; and the neutron＇s charge distribution.

关键词： Bethe-Salpeter equations bound-states confinement dynamical chiral symmetry breaking,dyson-Schwinger equations Faddeev equation nucleon electromagnetic form factors