On the strong effective coupling, glueball and meson ground states

The phenomena of strong running coupling and hadron mass generating have been studied in the framework of a QCD-inspired relativistic model of quark-gluon interaction with infrared confined propagators. We derived a meson mass equation and revealed a specific new behaviour of the mass-dependent strong coupling $\hat\alpha_s(M)$ defined in the time-like region. A new infrared freezing point $\hat\alpha_s(0)=1.03198$ at origin has been found and it did not depend on the confinement scale $\Lambda>0$. Independent and new estimates on the scalar glueball mass, 'radius' and gluon condensate value have been performed. The spectrum of conventional mesons have been calculated by introducing a minimal set of parameters: the masses of constituent quarks and $\Lambda$. The obtained values are in good agreement with the latest experimental data with relative errors less than 1.8 percent. Accurate estimates of the leptonic decay constants of pseudoscalar and vector mesons have been performed.