ORCID ID

https://orcid.org/0000-0002-6069-8215

Date Awarded

2021

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Physics

Advisor

Konstantinos Orginos

Committee Member

David Richards

Committee Member

David Armstrong

Committee Member

Christopher Monahan

Abstract

A comprehensive study of the gluonic content in the nucleon from a first principles lattice quantum chromodynamics calculation is presented. The unpolarized gluonic distribution in the nucleon is calculated using the pseudo-PDF framework on the lattice. First, the spectral analyses of the low-lying states in the nucleon, as well as in the delta are performed on the lattice, identifying baryons states with hybrid characteristics, in which the gluons play a manifestly structural role, and determining a set of operators which have significant overlaps onto the ground state of the nucleon. Techniques such as distillation for smearing the quark fields, momentum smearing to achieve a better signal at the higher momenta, the gradient flow technique for suppressing the gauge fluctuations, and the solution of the summed generalized eigenvalue problem employing a set of operators determined by the nucleon spectral analysis are implemented to calculate the gluonic matrix elements. A combination of these techniques provides the most precise lattice determination of the gluonic distribution in the nucleon to date. Short distance factorization provides the perturbative matching kernel which, in turn, allows one to calculate the gluon Ioffe-time distribution in the MS scheme at μ = 2 GeV. To accomplish this task, a parametrization in terms of Jacobi polynomials is used in an approximation in which the mixing with the quark singlet sector is neglected. Finally, the results are compared with the phenomenological determinations.

DOI

https://dx.doi.org/10.21220/s2-cs9x-vf49

Rights

© The Author

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