Width of Hadronic States and Radiative Corrections in QCD Sum Rules

Abstract

In hadronic physics, form factors play an important role in the description of the internal structure of the hadrons. However, their determinations are often complicated, since the non-perturbative QCD effects are directly related to the partonic distribution, such as the gluon exchange at high and low energies and also with the presence of the valence and the virtual quarks in the hadron nuclei. In general, these non-perturbative QCD effects are parameterized and form factors emerge as functions of the hadronic structure, providing the necessary basis for building QCD effective models. With the inclusion of form factors, these models are able to calculate cross sections between light and heavy hadrons with higher precision and can even provide answers about the production (and deletion) of the charmonium in collisions Nucleon-Nucleon produced at RHIC.The formalism used in this research project to study masses, form factors, decay widths and other hadronic parameters is the QCD Sum Rules.