evolution of the light meson resonances

The variation of the resonance poles, i.e., the mass and width, originating from changing the values of $$N_{\text {C}}$$, the number of the QCD colors, provide an intuitive theoretical method to discriminate the interior constituents of hadrons. Many different approaches, including unitarized chiral amplitudes, dispersive methods, quark models, linear-sigma-model-like framework, etc., have been widely used to determine the $$N_{\text {C}}$$ trajectories of the various resonance pole positions. We focus on the discussions of the light-flavor meson resonances in this work