Erlangen 2026 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 32: Heavy-Ion Collisions and QCD Phases V

HK 32.6: Vortrag

Donnerstag, 19. März 2026, 15:15–15:30, PHIL C 601

Critical Behavior of O(N) Model G in the large-N Limit — •Jonas Hirsch¹, Johannes V. Roth¹, and Lorenz von Smekal^1,2 — ¹Institut für Theoretische Physik, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, 35392 Giessen, Germany — ²Helmholtz Research Academy Hesse for FAIR (HFHF), Campus Giessen, 35392 Giessen, Germany

The chiral phase transition of QCD in the limit of two massless quark flavors is widely believed to be of second order in the O(4) universality class. Since the work of Rajagopal and Wilczek, its dynamic universality class is then expected to be an O(4) extension of the original Model G by Halperin and Hohenberg. The characteristic feature of this dynamic model is the reversible mode coupling between the conserved iso-(axial-)vector charges and the chiral condensate as the order parameter field which all relax at equal rates due to strong dynamic scaling [1]. In this talk, we will consider Model G with a generalized N-component order parameter, for which we perform the limit N→ ∞. We show exact results for the universal spectral function in the symmetric phase by using large-N counting rules for Dyson-Schwinger equations. Furthermore, we discuss an extension to the broken phase and a nonzero external source, which corresponds to a non-vanishing quark mass. Lastly, we investigate the loss of the strong-scaling fixed point, and how it could be recovered by NLO correction.
[1] J.V. Roth, Y. Ye, S. Schlichting, L. von Smekal, Dynamic critical behavior of the chiral phase transition from the real-time functional renormalization group, JHEP, vol. 01, 2025, p. 118

Keywords: Chiral Phase Transition; Dynamic Critical Phenomena; Dyson-Schwinger equations; QCD Phasediagram; Model G