Measurement of σ · B ( W → eν ) and σ · B ( Z 0 → e + e − ) in pp collisions at √ s = 1 . 8 TeV

We present a measurement of σ · B(W → eν) and σ · B(Z → ee) in proton antiproton collisions at √ s = 1.8 TeV using a significantly improved understanding of the integrated luminosity. The data represent an integrated luminosity of 19.7 pb from the 1992-1993 run with the Collider Detector at Fermilab (CDF). We find σ · B(W → eν) = 2.49 ± 0.12 nb and σ · B(Z → ee) = 0.231 ± 0.012 nb. PACS Numbers: 13.38.-b, 13.60.Hb, 14.70.-e Measurements of the product of the production cross section and the leptonic branching ratio for W and Z bosons, σ · B(W → eν) and σ · B(Z → ee), test the consistency of the standard model couplings [1], the understanding of higher order QCD contributions [2], and the parton distribution functions of the proton. In perturbation theory, the production cross section is predicted to next-to-next-to-leading order (NNLO), with ≈ 20% corrections to the leading order prediction from NLO and additional ≈ 3% corrections at NNLO [2]. In previous measurements at √ s = 1.8 TeV [3, 4, 5], the accuracy of the comparison to theoretical predictions has been limited by systematic uncertainties in the overall normalization and statistical uncertainties in the event samples. In Reference [6], CDF has presented the measured value of the ratio σ ·B(W → eν)/σ ·B(Z0 → ee) from the 1992-1993 data, but not the individual cross sections. In References [7, 8, 9], CDF has presented detailed