Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Dutta, Dipangkar

Committee Member

Jones, Mark

Committee Member

Winger, Jeff A.

Committee Member

Rupak Lan Tai Moong, Gautam

Committee Member

Crider, Benjamin P.

Date of Degree

12-10-2021

Document Type

Dissertation - Campus Access Only

Major

Physics

Degree Name

Doctor of Philosophy (Ph.D)

College

College of Arts and Sciences

Department

Department of Physics and Astronomy

Abstract

Color Transparency $(CT)$ is a unique prediction of Quantum Chromodynamics $(QCD)$ where the final (and/or initial) state interactions of hadrons with the nuclear medium are suppressed for exclusive processes at high momentum transfers. While this phenomenon has been observed for mesons, there has never been a conclusive observation for baryons. A clear signal of $CT$ for baryons would be the first evidence of baryons fluctuating to a small size in the nucleus, and the onset would show the transition from nucleon-meson picture to quark-gluon degrees of freedom. The experiment $E1206107$, searching for the onset of $CT$ in protons was completed in $Hall ~C$ at Jefferson Laboratory $(JLab)$ using the upgraded $12 ~GeV ~e^{-}$ beam. It used the High Momentum Spectrometer $(HMS)$ and the new Super High Momentum spectrometer $(SHMS)$ in coincidence to measure the $e+^{12}C \longrightarrow e'+p+X$ reaction in quasi-elastic kinematics. Data were collected on a $^{12}C$ target over the range of $Q^2=8-14.3~(GeV/c)^{2}$, covering the region where a previous $p+A \longrightarrow p'+p+X$ experiment at Brookhaven National Laboratory $(BNL)$ had observed an enhancement. Proton Transparency (PT) was extracted from these data. A rise in the $PT$ as a function of $Q^2$ (defined as the square of the negative of the 4-momentum transfer by the scattered electron) is predicted to be a signature of the onset of $CT$. Our data showed no significant increase and consistent with the traditional nuclear physics calculation. This \MakeLowercase{\doctype} discusses the theory and implementation of the $CT$ experiment, summarizes the data analysis and presents results on hydrogen normalization and nuclear transparency.

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