Measurement of W → l ν + jets Differential Cross Section with 9.0 fb -1
Authors: A. Driutti, G. Pauletta, V. Rusu, M. Trovato
Preliminary results for the production of a W boson in association with jets, in p collisions at √ p s= 1.96 TeV center mass energy are presented.
The measurement is based on the whole data set collected by CDF during Run II, which corresponds to an integrated luminosity of 9.0 fb -1. Cross section for the inclusive production of jets with E > 25 GeV and | T jet η| <2, in conjunction with a jet W boson which decays into an electron-neutrino or muon-neutrino pair, are presented as a function of E and inclusive jet multiplicity.
Background Modeling & Validation
Fig. 1: The leading jet E distribution for the T W (→ eν) + ≥ 1 jets sample (a) and W (→ μν) + ≥ 1 jets sample (b) in the control region. The lower figures illustrate the ratio between data distributions and predictions (see text).
Estimated and Observed Number of Events
Tab. 1: Estimated number of background events in 9.0 fb -1 for W (→ eν) + ≥ 1, 2, 3 and 4 jets and data yields.
Tab. 2: Estimated number of background events in 9.0 fb -1 for W (→ μν) + ≥ 1, 2, 3 and 4 jets and data yields.
Fig. 2: Data and background jet multiplicities in the W → eν channel (a) and in the W → μν channel (b). The LO×K-factor ALPGEN+PYTHIA theoretical prediction is also shown.
Fig. 3: Total systematic uncertainties vs inclusive jet multiplicity in the W → eν channel (a) and in the W → μν channel (b).
Fig. 4: Total systematic uncertainties vs leading jet E T in the W → eν channel (a) and in the W → μν channel (b).
Fig. 5: Measured cross section in the W (→ eν) + jets (blue dots) and W (→ μν) + jets (red squares) decay channels as a function of inclusive number of jets (a) and leading jet E T (b) in events with ≥ 1 jet. The lower figures illustrate the ratio between measured cross sections and combination with the total systematic uncertainty (all correlations are properly accounted for).
Fig. 6: Measured inclusive jet differential cross section (black dots) as a function of the inclusive jet multiplicity (a) and leading jet E T (b) compared to LO calculations corrected by K-factor pQCD predictions (open squares). The shaded bands show the total systematic uncertainty, except for the 6% luminosity uncertainty. The dashed and the plain lines indicate the PDF uncertainty and the variation of the renormalization scale μ, respectively. 0
Tab. 3: Unfolded W (→ lν)+jets cross section mesurements for inclusive jet multiplicities up to 4 jets together with statistical, systematic and luminosity uncertainties. The kinematic region in which the measurements are performed is E > 25 GeV and | T l η| <1, l E > 25 GeV and | T jet η| <2 and jet m > 40 GeV/c T W 2.