| dc.description |
Asymptotic Padé-approximant methods are utilized to estimate the O(α<sub>s</sub><sup>5</sup>) contribution to the H→gg rate and the O(α<sub>s</sub><sup>4</sup>) contribution to the H→bb̅ rate. The former process is of particular interest because of the slow convergence evident from the three known terms of its QCD series, which begins with an O(α<sub>s</sub><sup>2</sup>) leading-order term. The O(α<sub>s</sub><sup>5</sup>) contribution to the H→gg rate is expressed as a degree-three polynomial in L≡ln (µ<sup>2</sup>/m<sub>t</sub><sup>2</sup>(µ)). We find that asymptotic Padé-approximant predictions for the coefficients of L, L<sup>2</sup> and L<sup>3</sup> are, respectively, within 1%, 2% and 7% of true values extracted via renormalization-group methods. Upon including the full set of next-order coefficients, the H→gg rate is found to be virtually scale-independent over the 0.3M<sub>H</sub>~<µ~<M<sub>t</sub> range of the renormalization scale parameter µ. We conclude by discussing the small O(α<sub>s</sub><sup>4</sup>) contribution to the H→bb̅ rate, which is obtained from a prior asymptotic Padé-approximant estimate of the O(α<sub>s</sub><sup>4</sup>) contribution to the quark-antiquark scalar-current correlation function. |
