Decay widths and total cross sections in perturbative QCD
Abstract
The current status of analytic higherorder perturbative computations of total cross sections and decay widths in Quantum Chromodynamics is reviewed. Important issues are the methodology of renormalizationgroup evaluations, the ambiguities of the renormalization scheme and its scale, and the technical challenge of calculating manyloop diagrams. As examples, the authors consider the quantities σ_{tot}(e^{+}e^{}>hadrons) and Γ(τ^{}>ν_{τ}+hadrons) up to O(α^{3}_{s}) as well as Γ(H>hadrons) up to O(α^{2}_{s}). The evaluation of the fourloop QED beta function is also described. The problem of theoretical uncertainty estimates in perturbative calculations is briefly discussed.
 Publication:

Reviews of Modern Physics
 Pub Date:
 January 1996
 DOI:
 10.1103/RevModPhys.68.259
 arXiv:
 arXiv:hepph/9508351
 Bibcode:
 1996RvMP...68..259S
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 83 pages, LaTeX, Reviews of Modern Physics style, 14 figures plus figural equations (not included). Hard copy available upon request at levan@jet.uoregon.edu. To be published in Reviews of Modern Physics