We solve the light-front QCD Hamiltonian including, for the first time, gluons and sea quarks along with the valence quarks. Our fully relativistic, nonperturbative approach accurately describes the proton’s mass, electromagnetic form factors, axial and tensor charges, and Parton Distribution Functions (PDFs) at a defined scale. It highlights the impact of dynamical gluons and sea quarks on...
Unraveling the proton spin composition, comprising intrinsic spins and orbital angular momenta of quarks and gluons, stands as one of the most fundamental and challenging questions in QCD. Tremendous progress has been made since the first surprising result by the EMC experiment in the late 1980s, which significantly contribute to our understanding of this question. However, the helicity...
The study of the origins of transverse single-spin asymmetries has stimulated significant progress in the development of twist-3 formalism and transverse-momentum-dependent parton distribution functions (TMDs). Measurements of the azimuthal distribution of inclusive jets and identified hadrons within jets produced in transversely polarized hadronic interactions provide key insights into TMD...
A symmetry preserving treatment of a vector ⊗ vector contact interaction (SCI) is used as the basis for calculations of the two pion transverse momentum dependent parton distribution functions (TMDs); namely, that for unpolarised valence degrees-of-freedom and the analogous Boer-Mulders (BM) function. Amongst other things, the analysis enables the following themes to be addressed: the quark...
Using a symmetry-preserving formulation of a vector × vector contact interaction (SCI) and treating the proton as a quark + interacting-diquark bound state, whose structure is obtained by solving a Poincaré-covariant Faddeev equation, we provide a comprehensive, coherent set of predictions for unpolarised and polarised proton parton distribution functions(DFs): valence, glue, and four-flavour...
In this talk, I will present the first extraction of TMD helicity distributions, by analyzing double spin asymmetry data from SIDIS.
We will present the phenomenological extraction of Sivers and transversity distribution functions and Collins fragmentation functions by simultaneously fitting to semi-inclusive deep inelastic scattering (SIDIS) and electron-positron annihilation data. In addition, we investigate the impact of future SIDIS data from EicC on the extraction of TMDs.
In this letter we present a global analysis of Sivers function, transversity distribution functions and Collins fragmentation functions within TMD factorization. This analysis encompasses the latest data sets from semi-inclusive deep inelastic scattering, Drell-Yan, and $W^{\pm}/Z$-boson production as recently reported by the COMPASS and STAR Collaborations. Upon integrating this new data...
In large-momentum effective theory (LaMET), the transverse-momentum-dependent (TMD) light-front wave functions and soft functions can be extracted from the simulation of a four-quark form factor and equal-time correlation functions. In this work, using expansion by regions we provide a one-loop proof of TMD factorization of the form factor. For the one-loop validation, we also present a...
We study GPDs through pseudoscalar and vector meson production in electron-proton scattering.
GTMDs (Generalized transverse momentum distributions) are important non-perturbative inputs to depict the 3-dimensional structure of nucleons. We propose the method to access small-x gluon GTMDs from lepton-pair azimuthal angle dependence in time-like Compton scattering using Golec-Biernat-Wüsthoff model, which is parallel to the study in deeply virtual Compton scattering.
我们提出了一种用于计算末态是自旋为1/2的强子的T-odd横动量依赖的胶子碎裂函数的模型。我们的模型是基于一个类时不在壳的胶子能碎裂成一个强子和一个在壳的旁观者粒子。为了考虑胶子交换的效应，我们计算了胶子-胶子关联函数的所有可能的单圈图。四个图中有两个图对碎裂函数产生了贡献。我们给出了T-odd横动量依赖胶子碎裂函数的解析表达式，并且给出了碎裂函数对$z$和$k_T$依赖关系的数值结果。
