Bilocal Field Theory for Composite Scalar Bosons

We give a bilocal field theory description of a composite scalar with an extended binding potential that reduces to the Nambu–Jona-Lasinio (NJL) model in the pointlike limit. This provides a description of the internal dynamics of the bound state and features a static internal wave function, <inl...

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Main Author: Christopher T. Hill
Format: Article
Language:English
Published: MDPI AG 2024-02-01
Series:Entropy
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Online Access:https://www.mdpi.com/1099-4300/26/2/146
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author Christopher T. Hill
author_facet Christopher T. Hill
author_sort Christopher T. Hill
collection DOAJ
description We give a bilocal field theory description of a composite scalar with an extended binding potential that reduces to the Nambu–Jona-Lasinio (NJL) model in the pointlike limit. This provides a description of the internal dynamics of the bound state and features a static internal wave function, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ϕ</mi><mo>(</mo><mover accent="true"><mi>r</mi><mo stretchy="false">→</mo></mover><mo>)</mo></mrow></semantics></math></inline-formula>, in the center-of-mass frame that satisfies a Schrödinger–Klein–Gordon equation with eigenvalues <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>m</mi><mn>2</mn></msup></semantics></math></inline-formula>. We analyze the “coloron” model (single perturbative massive gluon exchange) which yields a UV completion of the NJL model. This has a BCS-like enhancement of its interaction, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∝</mo><msub><mi>N</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> the number of colors, and is <i>classically critical</i> with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>g</mi><mrow><mi>c</mi><mi>r</mi><mi>i</mi><mi>t</mi><mi>i</mi><mi>c</mi><mi>a</mi><mi>l</mi></mrow></msub></semantics></math></inline-formula> remarkably close to the NJL quantum critical coupling. Negative eigenvalues for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>m</mi><mn>2</mn></msup></semantics></math></inline-formula> lead to spontaneous symmetry breaking, and the Yukawa coupling of the bound state to constituent fermions is emergent.
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spelling doaj.art-32b2840b959d4ad09770c5a9ef051a812024-02-23T15:15:43ZengMDPI AGEntropy1099-43002024-02-0126214610.3390/e26020146Bilocal Field Theory for Composite Scalar BosonsChristopher T. Hill0Particle Theory Department, Fermi National Accelerator Laboratory, P. O. Box 500, Batavia, IL 60510, USAWe give a bilocal field theory description of a composite scalar with an extended binding potential that reduces to the Nambu–Jona-Lasinio (NJL) model in the pointlike limit. This provides a description of the internal dynamics of the bound state and features a static internal wave function, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ϕ</mi><mo>(</mo><mover accent="true"><mi>r</mi><mo stretchy="false">→</mo></mover><mo>)</mo></mrow></semantics></math></inline-formula>, in the center-of-mass frame that satisfies a Schrödinger–Klein–Gordon equation with eigenvalues <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>m</mi><mn>2</mn></msup></semantics></math></inline-formula>. We analyze the “coloron” model (single perturbative massive gluon exchange) which yields a UV completion of the NJL model. This has a BCS-like enhancement of its interaction, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>∝</mo><msub><mi>N</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> the number of colors, and is <i>classically critical</i> with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>g</mi><mrow><mi>c</mi><mi>r</mi><mi>i</mi><mi>t</mi><mi>i</mi><mi>c</mi><mi>a</mi><mi>l</mi></mrow></msub></semantics></math></inline-formula> remarkably close to the NJL quantum critical coupling. Negative eigenvalues for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>m</mi><mn>2</mn></msup></semantics></math></inline-formula> lead to spontaneous symmetry breaking, and the Yukawa coupling of the bound state to constituent fermions is emergent.https://www.mdpi.com/1099-4300/26/2/146bound statescompositenesscoloron
spellingShingle Christopher T. Hill
Bilocal Field Theory for Composite Scalar Bosons
Entropy
bound states
compositeness
coloron
title Bilocal Field Theory for Composite Scalar Bosons
title_full Bilocal Field Theory for Composite Scalar Bosons
title_fullStr Bilocal Field Theory for Composite Scalar Bosons
title_full_unstemmed Bilocal Field Theory for Composite Scalar Bosons
title_short Bilocal Field Theory for Composite Scalar Bosons
title_sort bilocal field theory for composite scalar bosons
topic bound states
compositeness
coloron
url https://www.mdpi.com/1099-4300/26/2/146
work_keys_str_mv AT christopherthill bilocalfieldtheoryforcompositescalarbosons