Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling

Abstract We construct a QCD coupling A $$ \mathcal{A} $$ (Q 2) in the Effective Charge (ECH) scheme of the canonical part d(Q 2) of the (inelastic) polarised Bjorken Sum Rule (BSR) Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2). In the perturbative domain, the coupling A $$ \m...

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Main Authors: César Ayala, Gorazd Cvetič
Format: Article
Language:English
Published: SpringerOpen 2024-12-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP12(2024)075
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author César Ayala
Gorazd Cvetič
author_facet César Ayala
Gorazd Cvetič
author_sort César Ayala
collection DOAJ
description Abstract We construct a QCD coupling A $$ \mathcal{A} $$ (Q 2) in the Effective Charge (ECH) scheme of the canonical part d(Q 2) of the (inelastic) polarised Bjorken Sum Rule (BSR) Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2). In the perturbative domain, the coupling A $$ \mathcal{A} $$ (Q 2) practically coincides with the perturbative coupling a(Q 2) [≡ α s (Q 2)/π] in the four-loop ECH renormalisation scheme. In the deep infrared (IR) regime, A $$ \mathcal{A} $$ (Q 2) behaves as suggested by the Holographic Light-Front QCD up to the second derivative. Furthermore, in contrast to its perturbative counterpart a(Q 2), the coupling A $$ \mathcal{A} $$ (Q 2) is holomorphic in the entire complex Q 2-plane with the exception of the negative semiaxis, reflecting the holomorphic properties of the BSR observable d(Q 2) [or: Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2)] as dictated by the general principles of the Quantum Field Theory. It turns out that the obtained coupling, used as ECH, reproduces quite well the experimental data for Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2) in the entire N f = 3 regime 0 < Q 2 ≲ 5 GeV2.
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spelling doaj-art-9f0f7c28daa7434f883c4a0cf7c581f72024-12-22T12:09:20ZengSpringerOpenJournal of High Energy Physics1029-84792024-12-0120241212210.1007/JHEP12(2024)075Towards unifying perturbative and Holographic Light-Front QCD via holomorphic couplingCésar Ayala0Gorazd Cvetič1Departamento de Ingeniería y Tecnologías, Sede La Tirana, Universidad de TarapacáDepartment of Physics, Universidad Técnica Federico Santa MaríaAbstract We construct a QCD coupling A $$ \mathcal{A} $$ (Q 2) in the Effective Charge (ECH) scheme of the canonical part d(Q 2) of the (inelastic) polarised Bjorken Sum Rule (BSR) Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2). In the perturbative domain, the coupling A $$ \mathcal{A} $$ (Q 2) practically coincides with the perturbative coupling a(Q 2) [≡ α s (Q 2)/π] in the four-loop ECH renormalisation scheme. In the deep infrared (IR) regime, A $$ \mathcal{A} $$ (Q 2) behaves as suggested by the Holographic Light-Front QCD up to the second derivative. Furthermore, in contrast to its perturbative counterpart a(Q 2), the coupling A $$ \mathcal{A} $$ (Q 2) is holomorphic in the entire complex Q 2-plane with the exception of the negative semiaxis, reflecting the holomorphic properties of the BSR observable d(Q 2) [or: Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2)] as dictated by the general principles of the Quantum Field Theory. It turns out that the obtained coupling, used as ECH, reproduces quite well the experimental data for Γ ¯ 1 p − n $$ {\overline{\Gamma}}_1^{\textrm{p}-\textrm{n}} $$ (Q 2) in the entire N f = 3 regime 0 < Q 2 ≲ 5 GeV2.https://doi.org/10.1007/JHEP12(2024)075The Strong CouplingDeep Inelastic Scattering or Small-x PhysicsResummation
spellingShingle César Ayala
Gorazd Cvetič
Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling
Journal of High Energy Physics
The Strong Coupling
Deep Inelastic Scattering or Small-x Physics
Resummation
title Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling
title_full Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling
title_fullStr Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling
title_full_unstemmed Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling
title_short Towards unifying perturbative and Holographic Light-Front QCD via holomorphic coupling
title_sort towards unifying perturbative and holographic light front qcd via holomorphic coupling
topic The Strong Coupling
Deep Inelastic Scattering or Small-x Physics
Resummation
url https://doi.org/10.1007/JHEP12(2024)075
work_keys_str_mv AT cesarayala towardsunifyingperturbativeandholographiclightfrontqcdviaholomorphiccoupling
AT gorazdcvetic towardsunifyingperturbativeandholographiclightfrontqcdviaholomorphiccoupling