[PAST EVENT] Physics Colloquium - Special Time

October 21, 2011
3pm - 4pm
Small Hall, Room 111
300 Ukrop Way
Williamsburg, VA 23185Map this location
Abstract: The proton is a unique bound state: we know its constituents, quarks
and gluons, and we have a fine theory, QCD, to describe the strong
force that binds these constituents together. However, two key
features make it a baffling system that defies intuition: the
confining property of the strong force, and the relativistic nature of
the system. Real understanding of the proton can only be claimed when
two goals are accomplished: precise calculations from first
principles, and the development of a meaningful picture that
accurately describes the system's dominant behaviour, likely via
effective degrees of freedom. The excitement and challenge of the
quest for this inutitive picture is well illustrated by the ongoing
research into the orbital angular momentum of the quarks. As
experiment provides new clues about the motion of the up, down, and
sea quarks, theory continues to make progress in the interpretation of
the data, and to confront fundamental questions concerning the very
definition of L in this context.