The more precise determination of hadronic contribution to muonic (g-2) factor and to alpha(M^2_z)

The hadronic vacuum-polarization contribution to the muon anomalous magnetic moment a µ ( hadr. ) and to the value of the eleectromagnetic coupling constant at q 2 = M 2 z are determined more precisely in connection with a new more exact value of the electronic width of ρ -meson. The QCD model with infinite number of vector mesons is used. The more precisely determined results are: a µ ( hadr. ) = 678(7) . 10 − 10 , δα hadr. ( M 2 z ) = 0 . 02786(6). The purpose of this work is to determine more precisely the contribution of strong inter-actions to the value of a µ ( hadr. ) and δα hadr. ( M 2 z ) obtained in papers [1,2]. There are two reasons to write this letter.