Pade-improved estimates of hadronic Higgs decay rates

Asymptotic Pade-approximant methods are utilized to estimate the O(alpha(s) (5)) contribution to the H --> gs rate and the O(alpha(s)(4)) contribution to the H --> b (b) over bar rate. The former process is of particular inter est because of the slow convergence evident from the three known terms of i ts QCD series, which begins with an O(alpha(s)(2)) leading-order term. The O(alpha(s)(5)) contribution to the H --> gg rate is expressed as a degree-t hree polynomial in L drop ln(mu(2)/m(t)(2)(mu)). We find that asymptotic Pa de-approximant predictions for the coefficients of L, L-2 and L-3 are, resp ectively, within 1%, 2% and 7% of true values extracted via renormalization -group methods. Upon including the full set of next-order coefficients, the H --> gs rate is found to he virtually scale-independent over the 0.3M(H) less than or similar to mu less than or similar to M-t range of the renorma lization scale parameter mu. We conclude by discussing the small O(alpha(s) (4)) contribution to the H --> b (b) over bar rate. which is obtained from a prior asymptotic Pade-approximant estimate of the O(alpha(s)(4)) contribu tion to the quark-antiquark scaler-current correlation function.