Degree Type

Dissertation

Date of Award

2019

Degree Name

Doctor of Philosophy

Department

Physics and Astronomy

Major

Nuclear Physics

First Advisor

James P. Vary

Abstract

We investigate quantum chromodynamics (QCD) in the non-perturbative regime with the light-front Hamiltonian formalism. Our explorations are from two aspects, the hadron bound states and the high energy scatterings.

We first study the heavy quarkonia system within the basis light-front quantization approach. We review solving the heavy quarkonium system in the valence Fock sector with effective Hamiltonian, and discuss how one could extend the framework to higher Fock space. We then study the properties of heavy quarkonia through electromagnetic processes, via elastic form factors, radiative transitions and decay constants. We investigate the effect of different current components, different magnetic projections of the states and different reference frames in the valence Fock sector calculation on the light front. We suggest preferred choices based on our analysis, and carry out numerical calculations of those quantities with the valence light-front wavefunctions. Comparisons are made with experimental data and other theoretical calculations.

We also apply the light-front Hamiltonian approach to a time-dependent problem, the quark nucleus scattering. We carry out an explicit evolution of the quark by decomposing the time-evolution operator into many time increments. We calculate the scattering cross sections and study the evolution of the quark in the color space and the coordinate space. We reveal interesting sub-eikonal effects on the quark’s transverse location.

Those studies also show exciting possibilities for future applications of QCD bound states and time-dependent problems in the non-perturbative quantum field theory.

Copyright Owner

Meijian Li

Language

en

File Format

application/pdf

File Size

203 pages

Included in

Physics Commons

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