Nonperturbative strong coupling at timelike momenta

• Verfasst von: Horak, Jan [VerfasserIn]
• Verfasst von: Pawlowski, Jan M. [VerfasserIn]
• Verfasst von: Turnwald, Jonas [VerfasserIn]
• Verfasst von: Urban, Julian M. [VerfasserIn]
• Verfasst von: Wink, Nicolas [VerfasserIn]
• Verfasst von: Zafeiropoulos, Savvas [VerfasserIn]
• Titel: Nonperturbative strong coupling at timelike momenta
• Verf.angabe: Jan Horak, Jan M. Pawlowski, Jonas Turnwald, Julian M. Urban, Nicolas Wink, and Savvas Zafeiropoulos
• E-Jahr: 2023
• Jahr: 21 April 2023
• Umfang: 13 S.
• Fussnoten: Gesehen am 06.07.2023
• Titel Quelle: Enthalten in: Physical review
• Ort Quelle: Ridge, NY : American Physical Society, 2016
• Jahr Quelle: 2023
• Band/Heft Quelle: 107(2023), 7 vom: Apr., Artikel-ID 076019, Seite 1-13
• ISSN Quelle: 2470-0029
• DOI: doi:10.1103/PhysRevD.107.076019
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1852063920

Abstract

We compute the strong coupling constant of Landau gauge QCD in the full complex momentum plane, both directly and via spectral reconstruction. In particular, we consider the Taylor coupling given by the product of ghost and gluon dressing functions. Assuming spectral representations for the latter, we first show that also the coupling obeys such a representation. The subsequent spectral reconstruction of the coupling data, obtained from 2+1 flavor lattice QCD results for the ghost and gluon, is based on a probabilistic inversion of this representation using Gaussian process regression with analytically enforced asymptotics. In contradistinction, our direct calculation relies on earlier reconstruction results for the ghost and gluon spectral functions themselves, as well as data obtained in functional QCD. Apart from its relevance for studies of resonances or scattering processes, the calculation also serves as a nontrivial benchmark of our reconstruction approach. The results show remarkable agreement, testifying to the reliability of the method.