Gravitational Form Factors and the Mechanical Structure of the Proton

The mechanical structure of the proton—encoded in spatial distributions of internal pressure, shear forces, and energy density—offers a new and rapidly evolving avenue of research in hadronic physics. These properties are accessed through matrix elements of the QCD energy-momentum tensor and provide insights beyond those revealed by traditional electromagnetic form factors. Recent theoretical advances and experimental breakthroughs, particularly via Deeply Virtual Compton Scattering (DVCS), have made it possible to explore these aspects of proton structure for the first time.

This talk will review key progress in probing the proton’s mechanical structure, with emphasis on DVCS measurements from both CLAS12 in Hall B and dedicated experiments in Hall A at Jefferson Lab, enabled by the 12 GeV upgrade. These studies are unveiling the internal dynamics of the proton with unprecedented resolution. Looking forward, future experiments at Jefferson Lab and the upcoming Electron-Ion Collider (EIC) will extend this reach, offering deeper insights into the QCD forces responsible for confinement, mass generation, and the emergence of hadronic matter.