Speaker: Gerald A. Miller (University of Washington)

Title: Singular Charge Density at the Center of the Pion?

Abstract: We relate the three-dimensional infinite momentum 
frame spatial charge density of the pion to its electromagnetic 
form factor. Diverse treatments of the measured form factor 
data including: phenomenological fits, non-relativistic quark 
models, the application of perturbative QCD, QCD sum rules, 
holographic QCD, and the Nambu Jona-Lasinio (NJL) model all lead 
to the result that the charge density at the center of the pion 
has a logarithmic divergence. Relativistic constituent quark 
models do not display this singularity. Future measurements 
planned for larger values of momentum transfer may determine 
whether or not a singularity actually occurs.