Application of Pade Approximants to Determination of alpha_s(M_Z^2) from   Hadronic Event Shape Observables in e+e- Annihilation
  We have applied Pade approximants to perturbative QCD calculations of event shape observables in e+e- --> hadrons. We used the exact O(alpha_s^2) prediction and the [0/1] Pade approximant to estimate the O(alpha_s^3) term for 15 observables, and in each case determined alpha_s(M_Z^2) from comparison with hadronic Z^0 decay data from the SLD experiment. We found the scatter among the alpha_s(M_Z^2) values to be significantly reduced compared with the standard O(alpha_s^2) determination, implying that the Pade method provides at least a partial approximation of higher-order perturbative contributions to event shape observables. 
P.N. Burrows, T. Abraha, M. Samuel, E. Steinfelds, H. Masuda