2025/09/19 by J. Ho, Ho, J., Amir H. Fariborz +3
Physics and Astronomy · #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2509.16380
Previous work has shown that mesonic fields in chiral Lagrangians can be systematically connected to quark-level operators in QCD sum rules through chiral-symmetry constrained and energy-independent scale factor matrices. This framework yields universal scale factors associated with each chiral nonet, whether composed of quark-antiquark (qq) or four-quark (qqqq) operators. Building on the demonstrated scale-factor universality for the K0^* isodoublet and a0 isotriplet scalar mesons, we develop a revised Gaussian QCD sum-rule methodology that extends the analysis to higher-dimensional isospin sectors. To access nonperturbative information about resonances arising from final-state interactions, we introduce a background-resonance interference approximation. This approximation successfully reproduces both πK scattering amplitude data and πη scattering predictions. It also motivates new resonance models that enhance the scale-factor analysis linking chiral Lagrangians to QCD sum rules. Within this refined framework, we explore the scale factors for the K0^* and a0 mesons across a sequence of increasingly detailed resonance models.