On the quark spectral function in QCD

• Verfasst von: Horak, Jan [VerfasserIn]
• Verfasst von: Pawlowski, Jan M. [VerfasserIn]
• Verfasst von: Wink, Nicolas [VerfasserIn]
• Titel: On the quark spectral function in QCD
• Verf.angabe: Jan Horak, Jan M. Pawlowski and Nicolas Wink
• E-Jahr: 2023
• Jahr: 10-10-2023
• Umfang: 29 S.
• Illustrationen: Illustrationen
• Fussnoten: Gesehen am 15.08.2024
• Titel Quelle: Enthalten in: SciPost physics
• Ort Quelle: Amsterdam : SciPost Foundation, 2016
• Jahr Quelle: 2023
• Band/Heft Quelle: 15(2023), 4, Artikel-ID 149, Seite 1-29
• ISSN Quelle: 2542-4653
• DOI: doi:10.21468/SciPostPhys.15.4.149
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1898748519

Abstract

We calculate the spectral function of light quark flavours in 2+1 flavour vacuum QCD in the isospin-symmetric approximation. We employ spectral Dyson-Schwinger equations and compute the non-perturbative quark propagator directly in real-time, using recent spectral reconstruction results from Gaussian process regression of gluon propagator data in 2+1 flavour lattice QCD. Our results feature a pole-like peak structure at time-like momenta larger than the propagator's gapping scale as well as a negative scattering continuum, which we exploit assuming an analytic pole-tail split during the iterative solution. The computation is augmented with a general discussion of the impact of the quark-gluon vertex and the gluon propagator on the analytic structure of the quark propagator. In particular, we investigate under which conditions the quark propagator shows unphysical complex poles. Our results offer a wide range of applications, encompassing the ab-initio calculation of transport as well as resonance properties in QCD.