Gravitational form factors of hadrons from lattice QCD

The gravitational form factors (GFFs) of hadrons encode the matrix elements of the energy-momentum tensor of QCD. These quantities describe how energy, spin, and various mechanical properties of hadrons are carried by their quark and gluon constituents, and can be constrained using the framework of...

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Main Author: Pefkou, Dimitra Anastasia
Other Authors: Shanahan, Phiala E.
Format: Thesis
Published: Massachusetts Institute of Technology 2023
Online Access:https://hdl.handle.net/1721.1/152959
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author Pefkou, Dimitra Anastasia
author2 Shanahan, Phiala E.
author_facet Shanahan, Phiala E.
Pefkou, Dimitra Anastasia
author_sort Pefkou, Dimitra Anastasia
collection MIT
description The gravitational form factors (GFFs) of hadrons encode the matrix elements of the energy-momentum tensor of QCD. These quantities describe how energy, spin, and various mechanical properties of hadrons are carried by their quark and gluon constituents, and can be constrained using the framework of lattice quantum chromodynamics (QCD). In this thesis, we explore the gravitational structure of hadrons through two main results. The first result [1] is an extraction of the gluon GFFs of the pion, nucleon, 𝜌 meson, and Δ baryon as functions of the squared momentum transfer 𝑡 in the region 0 ≤ −𝑡 < 2 GeV², as determined in a lattice QCD study at pion mass 𝑚 subscript 𝜋 = 450 MeV. By fitting the extracted GFFs, we extract various gluon contributions to the energy, pressure, and shear force distributions of the hadrons. We also obtain estimates for the corresponding gluon mechanical and mass radii, as well as the forward-limit gluon contributions to the momentum fraction and angular momentum of the four hadrons. Our results for the gluon GFFs of the proton were found to be in agreement with the first phenomenological extraction [2]. The second result [3] is a decomposition of the GFFs of the pion between the different quark flavor and gluon contributions, in the kinematic region 0 ≤ −𝑡 < 2 GeV², on a lattice ensemble with quark masses yielding pion mass 𝑚 subscript 𝜋 = 170 MeV. From these results, we obtain the renormalization scheme- and scale-independent total GFFs of the pion, which are in agreement with the momentum fraction sum rule and the nex-to-leading order chiral perturbation theory prediction for its 𝐷-term, which is a fundamental hadron charge related to the internal forces.
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spelling mit-1721.1/1529592023-11-14T03:07:42Z Gravitational form factors of hadrons from lattice QCD Pefkou, Dimitra Anastasia Shanahan, Phiala E. Massachusetts Institute of Technology. Department of Physics The gravitational form factors (GFFs) of hadrons encode the matrix elements of the energy-momentum tensor of QCD. These quantities describe how energy, spin, and various mechanical properties of hadrons are carried by their quark and gluon constituents, and can be constrained using the framework of lattice quantum chromodynamics (QCD). In this thesis, we explore the gravitational structure of hadrons through two main results. The first result [1] is an extraction of the gluon GFFs of the pion, nucleon, 𝜌 meson, and Δ baryon as functions of the squared momentum transfer 𝑡 in the region 0 ≤ −𝑡 < 2 GeV², as determined in a lattice QCD study at pion mass 𝑚 subscript 𝜋 = 450 MeV. By fitting the extracted GFFs, we extract various gluon contributions to the energy, pressure, and shear force distributions of the hadrons. We also obtain estimates for the corresponding gluon mechanical and mass radii, as well as the forward-limit gluon contributions to the momentum fraction and angular momentum of the four hadrons. Our results for the gluon GFFs of the proton were found to be in agreement with the first phenomenological extraction [2]. The second result [3] is a decomposition of the GFFs of the pion between the different quark flavor and gluon contributions, in the kinematic region 0 ≤ −𝑡 < 2 GeV², on a lattice ensemble with quark masses yielding pion mass 𝑚 subscript 𝜋 = 170 MeV. From these results, we obtain the renormalization scheme- and scale-independent total GFFs of the pion, which are in agreement with the momentum fraction sum rule and the nex-to-leading order chiral perturbation theory prediction for its 𝐷-term, which is a fundamental hadron charge related to the internal forces. Ph.D. 2023-11-13T19:57:20Z 2023-11-13T19:57:20Z 2023-09 2023-10-25T22:15:25.585Z Thesis https://hdl.handle.net/1721.1/152959 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Pefkou, Dimitra Anastasia
Gravitational form factors of hadrons from lattice QCD
title Gravitational form factors of hadrons from lattice QCD
title_full Gravitational form factors of hadrons from lattice QCD
title_fullStr Gravitational form factors of hadrons from lattice QCD
title_full_unstemmed Gravitational form factors of hadrons from lattice QCD
title_short Gravitational form factors of hadrons from lattice QCD
title_sort gravitational form factors of hadrons from lattice qcd
url https://hdl.handle.net/1721.1/152959
work_keys_str_mv AT pefkoudimitraanastasia gravitationalformfactorsofhadronsfromlatticeqcd