Nuclear Physics Seminar - Sylvester Joosten (Argonne National Lab) "Gravitational Form Factors and the Forces that Shape the Proton"
- Event Type
- Seminar/Symposium
- Sponsor
- Physics Department
- Location
- Rhondale Tso Seminar Room, Loomis 236
- Date
- Nov 10, 2025 1:00 pm
- Speaker
- Sylvester Joosten (Argonne National Lab)
- Contact
- Brandy Koebbe
- bkoebbe@illinois.edu
- Views
- 30
- Originating Calendar
- Physics - Nuclear Physics Seminar
Gravitational form factors (GFFs) have emerged as a powerful tool to explore the internal dynamics of protons and neutrons. As matrix elements of the QCD energy–momentum tensor, they encode how quarks and gluons generate the nucleon’s mass, momentum, and mechanical structure, intimately related to the phenomenon of confinement itself. In this seminar, I will present new experimental results on the gluonic GFFs, focusing on the J/ψ-007 experiment in Hall C at Jefferson Lab. The complete J/ψ-007 dataset, including di-muon events, provides unprecedented access to the gluon GFFs and reveals how gluons exert and balance forces that stabilize the nucleon. I will also discuss a new perspective on what the “size” of the proton means. In addition, I will summarize the experimental status of valence-quark GFFs and introduce an upcoming program to measure strange-quark GFFs via near-threshold φ electroproduction. The seminar will conclude with an outlook on future studies at Jefferson Lab and the Electron-Ion Collider.