NLO QCD corrections to five-jet production at LEP and the extraction of αs(MZ)

The highest exclusive jet multiplicity studied at LEP experiments is five. In this paper we compute the next-to-leading order QCD corrections to e + e ‐ annihilation to five jets, essentially closing the (pure) perturbative QCD studies of exclusive jetty final states at LEP. We compare fixed-order perturbative results with ALEPH data. We estimate hadronization corrections to five-jet observables using the event generator SHERPA, which employs the CKKW procedure to combine a reliable perturbative treatment of high-multiplicity jet final states with parton showers. We show that a competitive value of the strong coupling constant �sleft(MZright) = 0.1156+0.0041 −0.0034canbeextractedfromthedistributionofthefive− jetresolutionparameterandthefive − jetrateatLEP1andLEP2. DOI: https://doi.org/10.1007/JHEP11(2010)050 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-41855 Accepted Version Originally published at: Frederix, R; Frixione, S; Melnikov, K; Zanderighi, G (2010). NLO QCD corrections to five-jet production at LEP and the extraction of �s(MZ). Journal of High Energy Physics, (11):050. DOI: https://doi.org/10.1007/JHEP11(2010)050 ar X iv :1 00 8. 53 13 v1 [ he pph ] 3 1 A ug 2 01 0 Preprint typeset in JHEP style HYPER VERSION CERN-TH/2010-185 OUTP-1019P ZU-TH 11/10 NLO QCD corrections to five-jet production at LEP and the extraction of αs(MZ) Rikkert Frederix Institut für Theoretische Physik, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland Stefano Frixione PH Department, TH Unit, CERN, CH-1211 Geneva 23, Switzerland ITPP, EPFL, CH-1015 Lausanne, Switzerland