Hadron structures are rather complicated and highly nontrivial. Physically describing the internal structures of a hadron (e.g. nucleon) in 3D space is one of the key scientific goals of ongoing and upcoming projects like the JLab 22 GeV upgrades and electron-ion colliders (EICs). In this talk, I will present our recent developments towards understanding the relativistic electromagnetic and axial-vector structures of a moving spin-1/2 hadron (e.g. the proton) in terms of corresponding hadronic matrix elements and elastic form factors (FFs), emphasizing in particular the role associated with the spin of the system. Meanwhile, I will make detailed comparisons between light-front (LF) distributions and canonical elastic-frame distributions, and show explicitly their natural connection in the infinite-momentum limit. In this limit, a conjecture will also be discussed so as to make connection with the Large Momentum Effective Field Theory (LaMET). Some discussions on the nucleon axial and spin radii, as well as the intrinsic 3D spin distributions of the proton in the weak sector will also be presented. Finally, I will conclude my talk with some remarks on the relativistic effects within Poincaré symmetry, and some related ongoing/future experiments that can be well expected.

Biography

Dr. Yi Chen is now a postdoc working on Theoretical Particle and Nuclear Physics at Department of Physics, Tsinghua University, under the supervision of Prof. Bing-Song Zou. He earned his Ph.D. degree in 2025 from the University of Science and Technology of China (USTC) under the supervision of Prof. Qun Wang and Prof. Cédric Lorcé, and earned his Master degree in 2021 from the University of Chinese Academy of Sciences (UCAS) under the supervision of Prof. Guo-Liang Ma. His research mainly focuses on hadron structures, (elastic) form factors, 3D tomography of hadrons, spin effects, and some phenomenology related to the physics at electron-ion colliders (EICs), (anti)neutrino accelerators and electron-positron colliders.

Inviter: Jiang-Hao Yu