Jet physics in two-loop QCD: Recent developments and open issues

by Thomas GEHRMANN (CERN-TH)

Friday 17 Nov 2000, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

Jet production observables are among the most sensitive probes of QCD at high energy colliders, where they are used for example to determine the strong coupling constant. At present, the interpretation of jet production data within perturbative QCD is restricted to next-to-leading (NLO) calculations, with theoretical uncertainties being considerably larger than current experimental errors. The extension of jet calculations to NNLO requires various ingredients, such as two-loop corrections to multi-leg amplitudes, multiple collinear limits of tree amplitudes, as well as a consistent method for the numerical computation of jet observables from NNLO parton level cross sections. We review recent progress made on these subjects and discuss the remaining open issues needed in particular for the two-loop calculation of three jet production and event shape observables in electron-positron annihilation.