From Partons to Hadrons: A Comprehensive QCD Study of Hadronic Structure

Recent years have seen major advances in the study of hadronic structure driven by high-precision data, increasingly sophisticated global analyses, progress in lattice QCD, and the emergence of new facilities such as the Electron-Ion Collider (EIC) and Future Circular Collider (FCC). At the same time, several fundamental challenges remain unresolved. These include achieving precision control of parton distribution functions (PDFs) and nuclear PDFs across wide kinematic regions; understanding fragmentation and hadronization mechanisms beyond leading approximations; constraining generalized and transverse-momentum-dependent parton distributions (GPDs/TMDs); and clarifying the role of diffraction, saturation, and small-x dynamics in QCD. Another important frontier concerns the mechanical structure of hadrons, including pressure, shear force, and angular-momentum distributions. Addressing these problems requires closer integration of perturbative and non-perturbative QCD approaches, phenomenological extractions, lattice-QCD inputs, and precision measurements from present and future experimental programs.This Research Topic aims to provide a timely and comprehensive overview of current progress and emerging directions in the QCD study of hadron and nuclear structure. The collection is motivated by the rapid convergence of precision phenomenology, first-principles calculations, and new experimental opportunities, particularly in the context of the EIC era and ongoing programs at CERN, Jefferson Lab, RHIC, and other facilities.A central objective is to address key challenges limiting the next generation of precision QCD studies, including the consistent treatment of uncertainties in global analyses, the interplay between perturbative and non-perturbative dynamics, the universality and evolution of multidimensional distributions, and the interpretation of increasingly precise experimental observables. The Research Topic will foster concrete cross-disciplinary dialogue by bringing together communities working on lattice QCD, global fits, effective theories, collider phenomenology, and experimental measurements within a single coordinated collection. By emphasizing connections between theoretical developments, phenomenological frameworks, and experimental constraints, the issue aims to identify common challenges, consolidate state-of-the-art methodologies, and help define priorities for future investigations.We welcome Original Research, Review/Mini-Review, and Methods articles addressing theoretical, phenomenological, computational, and experimental aspects of hadron and nuclear structure in QCD. Topics of interest include, but are not limited to:1- PDFs, nPDFs, helicity and transversity distributions, uncertainty quantification, and global analyses2- Fragmentation functions, hadronization dynamics, universality studies, and precision SIDIS/pp observables3- Elastic, transition, and gravitational form factors, including mechanical properties of hadrons4- GPDs, TMDs, factorization frameworks, evolution equations, and multidimensional tomography5- Diffraction, small-x physics, saturation phenomena, and related effective approaches6- Connections between lattice-QCD calculations, effective theories, and data-driven extractions7- Novel observables, AI/data-science-assisted analyses, and future opportunities at the EIC, FCC and related facilitiesParticular emphasis will be placed on contributions that connect complementary approaches or combine theoretical developments with phenomenological and experimental applications. Topic editors: Kazem Azizi, Hamzeh Khanpour, Shahram Jalalzadeh, Muhammad Goharipour Source: https://www.frontiersin.org/research-topics/78560/from-partons-to-hadrons-a-comprehensive-qcd-study-of-hadronic-structure