[Theory-seminars] now: final lecture Ben Bakker (today Wed. 10:30am, room L104)

[Bernhard Musch]

Dear all,

we have our final lecture by Ben Bakker now in room L104. A summary of 
the information follows:


Ben Bakker, Vrije Universiteit Amsterdam

*Light-front dynamics; Principles and applications*

today May 11, 10:30 am, room L104

Light-front dynamics (LFD), also known as front-form dynamics, is on of
the three form 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.



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A complete list of upcoming theory seminars and talks from previous
seminars are available from:
http://www.jlab.org/~prokudin/seminars/

Alexei, Berni and Satoshi
JLab Theory Seminar Organizers