Quantum Chromodynamic Quark Model Analysis of Hadron Elastic and Transition Form Factors
Chueng-Ryong Ji, Ho-Meoyng Choi, Ted Horton, and Daniel Arndt, North Carolina State University
Alex Pang, University of British Columbia
Research Objectives
The main objective of this project is to calculate the form factors of hadrons and compare them with experimental data. For the lower and higher momentum transfer regions, we use a quantum chromodynamic (QCD) motivated relativistic quark model and perturbative QCD, respectively.
Computational Approach
To simplify the spinor algebra, we have devised techniques which avoid manipulating any non-abelian matrices but instead involve only ordinary algebraic terms. We implemented our technique in Maple.
Accomplishments
We have calculated various transition form factors and radiative decays of pseudoscalar, vector, and axial vector mesons using the light-front quark model. We extended the calculation to cover the analysis of mass spectra and mixing angles of meson nonets.
Significance
Finding evidence of the quark and gluon effects inside hadrons and nuclei is one of the most significant goals of experiments at the Thomas Jefferson National Accelerator Facility (JLab). Our work provides theoretical guidance to achieve this goal.
Publications
A. Szczepaniak, C.-R. Ji, and A. Radyushkin, "A consistent analysis of the 
corrections to the pion elastic form factor," Phys. Rev. D 57, 2813 (1998).
S. J. Brodsky, C.-R. Ji, A. Pang, and D. Robertson, "Optimal renormalization scale and scheme for exclusive processes," Phys. Rev. D 57, 245 (1998).
H. M. Choi and C.-R. Ji, "Relations among the light-cone quark models with the invariant meson mass scheme and the model prediction of 
mixing," Phys. Rev. D 56, 6010 (1997).