# Lecture Series

## Upcoming

**Theory Center Lecture Series **Mon., May 9, 1:00 p.m. Tues., May 10, 1:00 p.m. Wed., May 11, 10:30 a.m. *All lectures will be held in CEBAF Center, Room L104*

Ben Bakker Vrije University, The Netherlands

**Light-Front Dynamics: Principles and Applications **

Light-front dynamics (LFD), also known as front-form dynamics, is one of the three forms of relativistic Hamiltonian dynamics distinguished by Dirac (1949). At the time Dirac's seminal paper appeared, quantum field theory was in a state of rapid development and its manifestly-covariant formulation all but eclipsed the older Hamiltonian formalism. The latter experienced a revival when the usefulness of the "infinite-momentum frame" was discovered for current algebra and used by Weinberg (1966) to propose a "dynamics at infinite momentum." Since then, LFD has been developed by many different groups, mainly with the motivation to obtain a viable non-perturbative treatment of strongly-interacting systems, in particular for QCD, at the amplitude level. In the lectures, LFD will be discussed in the first place as an example of a Hamiltonian framework, in comparison with the two other forms, instant-form and point-form dynamics. Next, two topics will be highlighted, namely the treatment of bound states, and the occurrence of "light-front singularities," i.e., singularities that do not occur in the manifestly-covariant treatment of the same systems, being specific to the LF formulation. It will be shown that these singularities can be tamed rather easily in perturbation theory, but also that their occurrence is more serious when bound states are looked for.

## Archive

*The transverse spin and momentum structure of hadrons*

Leonard Gamberg, Penn State University

*Lecture 1*: Wed., March 24, 2010*Lecture 2*: Fri., March 26, 2010*Lecture 3*: Mon., March 29, 2010

*Transverse Thinking: An Introduction to TMDs*

Alessandro Bacchetta, Jefferson Lab

*Lecture 1*: Wednesday, February 11, 2009 (12:00 p.m., L104)*Lecture 2*: Wednesday, February 25, 2009 (TBA)

*Poincare Invariant Quantum Mechanics*

Wayne Polyzou, University of Iowa

*Lecture 1*: Wednesday, May 21, 2008 (3:00 p.m., L104)*Lecture 2*: Friday, May 23, 2008 (1:00 p.m., L104)

**Hadronic Physics: from Quarks to Nuclei**

Virginia Physics Consortium Lecture Course

Wally Melnitchouk, Jefferson Lab

- September - December, 2006