Ma. Samuel et E. Steinfelds, PERTURBATIVE QUANTUM CHROMODYNAMICS - EVIDENCE THAT ALPHA-S RUNS, Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields, 107(6), 1994, pp. 831-835
We consider the theoretical predictions of perturbative quantum chromo
dynamics (QCD) for the quantities Re+e-, R(tau) and GAMMA(hadronic)Z0.
Using alpha(s)(M(tau)) = = 0.34(-0.05)+0.04), we find that alpha(s)(3
4 GeV) = 0.140(-0.008)+0.006 in agreement with the value extracted fro
m experiment, alpha(s)(34 GeV) = 0.148(22), and alpha(s)(M(Z)) = 0.119
(5), in excellent agreement with the experimental value from LEP, alph
a(s)(M(Z)) = 0.120(7). We show that using only the above value for alp
ha(s) (M-) as input and no free parameters we can predict alpha(s) (mu
) for M(tau) less-than-or-equal-to mu less-than-or-equal-to 200 GeV. O
ur result is in agreement with all known experimental values. Thus it
can be seen that alpha(s) truly runs, in agreement with perturbative Q
CD.