Abstrakt
We present a comprehensive analysis of inclusive W(-> ev) + n-jet (n >= 1, 2, 3, 4) production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV at the Tevatron collider using a 3.7 fb(-1) data set collected by the D0 detector. Differential cross sections are presented as a function of the jet rapidities (y), lepton transverse momentum (P-T) and pseudorapidity (eta), the scalar sum of the transverse energies of the W boson and all jets (H-T), leading dijet P-T and invariant mass, dijet rapidity separations for a variety of jet pairings for P-T-ordered and angular-ordered jets, dijet opening angle, dijet azimuthal angular separations for P-T-ordered and angular-ordered jets, and W boson transverse momentum.
The mean number of jets in an event containing a W boson is measured as a function of H-T, and as a function of the rapidity separations between the two highest-P-T jets and between the most widely separated jets in rapidity. Finally, the probability for third-jet emission in events containing a W boson and at least two jets is studied by measuring the fraction of events in the inclusive W + 2-jet sample that contain a third jet over a P-T threshold.
The analysis employs a regularized singular value decomposition technique to accurately correct for detector effects and for the presence of backgrounds. The corrected data are compared to particle level next-to-leading-order perturbative QCD predictions, predictions from all-order resummation approaches, and a variety of leading-order and matrix element plus parton shower event generators.
Regions of the phase space where there is agreement or disagreement with the data are discussed for the different models tested.