2020/08/31 by Fabio L. Braghin, Fábio L. Braghin
Physics and Astronomy · #Coupling (piping) #Coupling constant #Gluon #High-Energy Particle Collisions Research #Meson #Order (exchange) #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Pseudoscalar #Pseudoscalar meson #Quantum Chromodynamics and Particle Interactions #Quark #Scalar (mathematics) #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.103.094028
published as Phys. Rev. D 103, 094028 (2021) · 18 pages, revised, improved and extended version, accepted for publication
arxiv created 2021/04/29 · openalex publication_date 2021/05/24 · arxiv updated 2021/06/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A nonperturbative one-gluon exchange quark-antiquark interaction is considered to compute flavor-dependent U(3) Nambu--Jona-Lasinio-type (NJL-type) interactions of the form G_ij,\mathrm\ensuremathΓ(\ensuremathψ\ensuremathλi\mathrm\ensuremathΓ\ensuremathψ)(\ensuremathψ\ensuremathλj\mathrm\ensuremathΓ\ensuremathψ) for i,j=0…8 and \mathrm\ensuremathΓ=I,i\ensuremathγ5 from the one-loop polarization process with nondegenerate u-d-s quark effective masses. The resulting NJL-type coupling constants in all channels are resolved in the long-wavelength limit and the numerical results are presented for different choices of an effective gluon propagator. Leading deviations with respect to a flavor symmetric coupling constant are found to be of the order (M_f2*\ensuremath-M_f1*)n/(M_f2*+M_f1*)n, for n=1, 2, where M_fi* are the effective masses of quarks f1,f2=u, d and s. The scalar channel coupling constants Gij,s can be considerably smaller than the pseudoscalar ones. The effect of the flavor-dependence of coupling constants for the masses of pions and kaons may be nearly of the same order of magnitude as the effect of the u, d, and s quark mass nondegeneracy. The effect of these coupling constants is also verified for some of the light scalar meson masses, usually described by quark-antiquark states, and for some observables of the pseudoscalar mesons.