In contrast to the nucleon, the elastic form factor of the pion is unique in that it can be rigorously calculated (in the limit of asymptotically large momentum transfer) using perturbative QCD. However, the lack of a "free pion" target makes experimental studies of this quantity challenging, and one must make measurements using the virtual pion cloud of the nucleon via pion electroproduction.
This talk will describe the pion form factor program at Jefferson Lab, where experiments at 6 GeV have provided precise measurements of the form factor at moderate momentum transfers, while future measurements using the upgraded, 12-GeV beam will allow us to extend these measurements to even larger momentum transfer. In addition, I will discuss recently published measurements of (L-T separated) charged pion ratios. These measurements provide insight into the pion electroproduction reaction mechanism and may provide interesting information about the so-called transversity GPD.
Argonne Physics Division Seminar Schedule