Nonperturbative strong coupling at timelike momenta

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,...

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Hauptverfasser: Horak, Jan (VerfasserIn) , Pawlowski, Jan M. (VerfasserIn) , Turnwald, Jonas (VerfasserIn) , Urban, Julian M. (VerfasserIn) , Wink, Nicolas (VerfasserIn) , Zafeiropoulos, Savvas (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 21 April 2023
In: Physical review
Year: 2023, Jahrgang: 107, Heft: 7, Pages: 1-13
ISSN:2470-0029
DOI:10.1103/PhysRevD.107.076019
Online-Zugang:Verlag, kostenfrei, Volltext: https://doi.org/10.1103/PhysRevD.107.076019
Verlag, kostenfrei, Volltext: https://link.aps.org/doi/10.1103/PhysRevD.107.076019
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Verfasserangaben:Jan Horak, Jan M. Pawlowski, Jonas Turnwald, Julian M. Urban, Nicolas Wink, and Savvas Zafeiropoulos
Beschreibung
Zusammenfassung: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.
Beschreibung:Gesehen am 06.07.2023
Beschreibung:Online Resource
ISSN:2470-0029
DOI:10.1103/PhysRevD.107.076019