Kg. Chetyrkin, CORRELATOR OF THE QUARK SCALAR CURRENTS AND GAMMA(TOT)(H-]HADRONS) ATO(ALPHA(S)(3)) IN PQCD, Physics letters. Section B, 390(1-4), 1997, pp. 309-317
We present the results of the analytical evaluation of the massless fo
ur-loop O(alpha(s)(3)) correction to the correlator of the quark scala
r currents and the Higgs decay rate into hadrons. In numerical form we
found (in <(MS)over bar> scheme) that Gamma(H --> (b) over bar b) = (
3G(F)/4 root 2 pi) M(H)m(b)(2)(M(H)) [1 + 5.667 alpha(s)/pi + (35.94 -
1.359n(f)) (alpha(s)/pi)(2) + (164.139 - 25.771n(f) + 0.259n(f)(2)) (
alpha s/pi(3)] where n(f) is the number of quark flavour and alpha(s)
= alpha(s)(M(H)).