2003/05/31 by Masayasu Harada, Masafumi Kurachi, Koichi Yamawaki · 42 citations
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Geometry #High-Energy Particle Collisions Research #Massless particle #Mathematical physics #Mathematics #Meson #Particle physics #Physics #Pseudoscalar #Pseudoscalar meson #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quark #Scalar (mathematics) #hep-ph
paper · pdf · doi:10.1103/physrevd.68.076001
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 68(7) (American Physical Society) · 33 pages, 16 figures. Typos are corrected. Minor corrections and references are added. Version to appear in Phys. Rev. D
arxiv created 2003/09/24 · openalex publication_date 2003/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We solve the homogeneous Bethe-Salpeter (HBS) equation for the scalar, pseudoscalar, vector, and axial-vector bound states of quarks and antiquarks in large Nf QCD with the improved ladder approximation in the Landau gauge. The quark mass function in the HBS equation is obtained from the Schwinger-Dyson (SD) equation in the same approximation for consistency with the chiral symmetry. Amazingly, because of the fact that the two-loop running coupling of large Nf QCD is explicitly written in terms of an analytic function, large Nf QCD turns out to be the first example in which the SD equation can be solved in the complex plane and hence the HBS equation directly in the time-like region. We find that approaching the chiral phase transition point from the broken phase, the scalar, vector, and axial-vector meson masses vanish to zero with the same scaling behavior, all degenerate with the massless pseudoscalar meson. This may suggest a new type of manifestation of the chiral symmetry restoration in large Nf QCD.