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Title: Effective field theories of baryons and mesons, or, what do quarks do?

Abstract

This thesis is an attempt to understand the properties of the protons, pions and other hadrons in terms of their fundamental building blocks. In the first chapter the author reviews several of the approaches that have already been developed. The Nambu-Jona-Lasinio model offers the classic example of a derivation of meson properties from a quark Lagrangian. The chiral quark model encodes much of the intuition acquired in recent decades. The author also discusses the non-linear sigma model, the Skyrme model, and the constituent quark model, which is one of the oldest and most successful models. In the constituent quark model, the constituent quark appears to be different from the current quark that appears in the fundamental QCD Lagrangian. Recently it was proposed that the constituent quark is a topological soliton. In chapter 2 the author investigates this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. In chapter 3 the author uses a different plan of attack. Rather than trying to model the constituents of the baryon, he begins with an effective fieldmore » theory of baryons and mesons, with couplings and masses that are simply determined phenomenologically. Meson loop corrections to baryon axial currents are then computed in the 1/N expansion. It is already known that the one-loop corrections are suppressed by a factor 1/N; here it is shown that the two-loop corrections are suppressed by 1/N{sup 2}. To leading order, these corrections are exactly the same as would be calculated in the constituent quark model. This method therefore offers a different approach to the constituent quark.« less

Authors:
 [1]
  1. Lawrence Berkeley Lab., CA (United States). Theoretical Physics Group
Publication Date:
Research Org.:
Lawrence Berkeley Lab., CA (United States); California Univ., Berkeley, CA (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
OSTI Identifier:
95261
Report Number(s):
LBL-37440
ON: DE95016440; CNN: Grant PHY-90-21139; TRN: 95:018650
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: TH: Thesis (Ph.D.); PBD: 26 Jun 1995
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; BARYONS; FIELD THEORIES; MESONS; QUARK MODEL; LAGRANGIAN FUNCTION; CHIRAL SYMMETRY; SIGMA MODEL; QUANTUM CHROMODYNAMICS; THEORETICAL DATA; PARTICLE PROPERTIES; RENORMALIZATION

Citation Formats

Keaton, G L. Effective field theories of baryons and mesons, or, what do quarks do?. United States: N. p., 1995. Web. doi:10.2172/95261.
Keaton, G L. Effective field theories of baryons and mesons, or, what do quarks do?. United States. doi:10.2172/95261.
Keaton, G L. Mon . "Effective field theories of baryons and mesons, or, what do quarks do?". United States. doi:10.2172/95261. https://www.osti.gov/servlets/purl/95261.
@article{osti_95261,
title = {Effective field theories of baryons and mesons, or, what do quarks do?},
author = {Keaton, G L},
abstractNote = {This thesis is an attempt to understand the properties of the protons, pions and other hadrons in terms of their fundamental building blocks. In the first chapter the author reviews several of the approaches that have already been developed. The Nambu-Jona-Lasinio model offers the classic example of a derivation of meson properties from a quark Lagrangian. The chiral quark model encodes much of the intuition acquired in recent decades. The author also discusses the non-linear sigma model, the Skyrme model, and the constituent quark model, which is one of the oldest and most successful models. In the constituent quark model, the constituent quark appears to be different from the current quark that appears in the fundamental QCD Lagrangian. Recently it was proposed that the constituent quark is a topological soliton. In chapter 2 the author investigates this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. In chapter 3 the author uses a different plan of attack. Rather than trying to model the constituents of the baryon, he begins with an effective field theory of baryons and mesons, with couplings and masses that are simply determined phenomenologically. Meson loop corrections to baryon axial currents are then computed in the 1/N expansion. It is already known that the one-loop corrections are suppressed by a factor 1/N; here it is shown that the two-loop corrections are suppressed by 1/N{sup 2}. To leading order, these corrections are exactly the same as would be calculated in the constituent quark model. This method therefore offers a different approach to the constituent quark.},
doi = {10.2172/95261},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {6}
}