Speaker: Peter Schweitzer (U. Connecticut)
Title: The Energy-Momentum Tensor Form Factors of the Nucleon
Abstract:
Enormous efforts are being devoted to measurements of observables
in hard exclusive reactions related to generalized parton distributions
(GPDs), and considerable progress has been made in this field recently,
at Jefferson Lab and at other facilities. A prominent feature of GPDs
justifying these efforts is that they allow to access through Ji's sum
rule the form factor J^Q(t), whose value at zero momentum transfer tells
us the fraction of the nucleon spin due to (spin + orbital momentum of)
quarks. However, the information content of GPDs is far richer than that.
For example, GPDs allow to access the form factors of the energy momentum
tensor. The nucleon, having spin 1/2, has 3 such form factors, one of them
being our J^Q(t). The other two are related to the distribution of
matter and strong forces in the nucleon --- just like, for example, the
electric form factor is related to the electric charge distribution.
The purpose of this talk is to highlight, on the example of calculations
from soliton models, what kind of fascinating new insights into the nucleon
structure we are going to gain from these form factors.