Determination of the strong coupling constant (α<sub>s</sub>) and a test of perturbative QCD using W + jets processes in the D0 detector

Abstract

The D0 experiment has accumulated data for a study of inclusive W production corresponding to a total integrated luminosity of 14.3 {plus_minus} 1.7 pb{sup {minus}1} during the 1992--1993 Fermilab Tevatron collider run. The total number of W {yields} e + {nu} candidates is 9770. The ratio of the number of W + 1 jet events to that of W + 0 jet events has been measured as a function of jet minimum E{sub T}. Using this ratio the strong coupling constant, {alpha}{sub s} at Q{sup 2} = M{sub W}{sup 2} is measured to be {alpha}{sub s}(M{sub W}{sup 2}) = 0.124 {plus_minus} 0.005(stat) {plus_minus} 0.006(MC) {plus_minus} 0.008(theory){sub {minus}0.022}{sup +0.026}(sys) or ({sub {minus}0.025}{sup +0.028} combined) with a jet minimum E{sub T} of 25 GeV. A quantitative test of perturbative QCD has been made by comparing the experimentally measured ratio with the theoretical predictions. The theoretical predictions of the ratio in both the leading order and next-to-leading order are in good agreement with the measured ratio.