Events on Monday, April 13th, 2026
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Overview of Fusion at ORNL
- Time: 12:00 pm - 1:00 pm
- Place: Engineering Hall - 1227
- Speaker: Dr. Troy Carter, Oak Ridge National Laboratory
- Abstract: Oak Ridge National Laboratory (ORNL) has a long and storied history of contributions to fusion research spanning plasma physics, fusion materials, and fusion enabling technologies. I will highlight ORNL’s capabilities and recent contributions across the fusion energy landscape, including the development of facilities (e.g. the Materials Plasma Exposure eXperiment (MPEX)) and science and technology advances (e.g. developing exhaust solutions for future fusion devices, enabling record performance on Wendelstein 7-X through pellet fueling and progress on assessing blanket concepts including both modeling and experiments). Partnerships are essential on our path to commercialize fusion energy: I will also discuss how ORNL is working to build partnerships with the private sector, universities, state and local government and regional organizations with the goal of addressing science and technology gaps, building the needed fusion workforce and stimulating regional supply chain development.
- Host: Cary Forest
- Theory Seminar (High Energy/Cosmology)
- Constructibility of Massive Helicity Amplitudes and the ALT Shift
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Zhen Liu, Minnesota U.
- Abstract: Recursive constructions in amplitudes are a strong feature that requires careful analytic continuation with momentum shift to yield the full, correct, physical amplitudes. If not done systematically, an undetermined contact term would arise. We study the All-Line Transverse (ALT) shift, which we developed for on-shell recursion of amplitudes for particles of any mass. Our method allows for a nice and clean determination of the constructibility of the underlying theory. We apply the shift to the QED, electroweak theory, and higher-spin Compton scattering. The ALT shift framework allows consistent treatment in dealing with contact term ambiguities for renormalizable massive and massless theories, which we show can be useful in studying real-world amplitudes with massive spinors. Event recording:
- Host: Joshua Foster