Two-loop calculations for the propagators of gluonic currents

Abstract

We calculate two-loop corrections to the propagators of gluonic currentsjPG=αGμvaG¯μv and jSG = (β(α)/α)Gμν2. The results of the calculations are used for finding the connection between the characteristic scales of quark and gluon worlds in perturbative QCD and for an estimate of the mass of the first radial excitation of the η′ meson [we obtain (mη′)1 = 1.55GeV].