| Dissertation Abstract–Idaho State University (2018)
Quantum chromodynamics (QCD) is the fundamental theory underlying the strong inter-action. Great effort has been dedicated to explain hadron interactions and the hadron composition in terms of the QCD degrees of freedom. However, this task has been largely complicated by confinement which prevents us from a direct experimental study of the dy-namics of quarks and gluons. Instead, QCD-inspired models have been developed to explain the hadron spectrum, and while there has been success in explaining important features of it, many of the states that have been predicted by these models have not been found ex-perimentally. Furthermore, the hadronic spectrum is complicated to analyze because of a high number of excited states of the nucleon which have large widths that cause resonances to overlap. Additionally, we will need measurements of observables, coming from polarized beam and polarized target experiments, to obtain a complete measurement of all the helicity amplitudes.
My current research aims at contributing to a larger experimental program that seeks to shed light on the evolving status of the proton spectrum. I focus on the photoproduction of ω mesons off the bound proton, which is of great interest in providing information about N∗ resonances as ω is an isospin filter. I have extracted a preliminary quasi-free γd →
ωp(n) photon beam asymmetry polarization observable from CLAS data. The ω meson was identified through its charged decay ω → π+π−π0 where the π0 subsequently decays in two photons. The data were taken during the E06-103 experiment with the CLAS detector in Hall B at the Thomas Jefferson National Accelerator Laboratory (JLab). The experiment used the Hall-B Coherent Bremsstrahlung Facility to provide a high quality beam of linearly-polarized photons in the energy range from 1.1 to 2.3 GeV.Key Words: Hadron, Hadron Spectroscopy, Photoproduction, Polarization Observables. |