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

R Frederix, S Frixione, K Melnikov, G Zanderighi
2010
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
more » ... liable perturbative treatment of high-multiplicity jet final states with parton showers. We show that a competitive value of the strong coupling constant _sleft( M_Z right) = 0.1156 +0.0041 −0.0034 canbeextractedf romthedistributionof thef ive− jetresolutionparameterandthef ive − jetrateatLEP 1andLEP 2. Abstract: 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 highmultiplicity jet final states with parton showers. We show that a competitive value of the strong coupling constant α s (M Z ) = 0.1156 +0.0041 −0.0034 can be extracted from the distribution of the five-jet resolution parameter and the five-jet rate at LEP1 and LEP2.
doi:10.5167/uzh-41855 fatcat:rgbzb3djszezlayoxzknfdfp54