The O͑␣͒ electroweak radiative corrections to the process p p h→W Ϯ →l Ϯ (l ϭe,) are calculated. The O͑␣͒ corrections can be decomposed into separate gauge invariant contributions to the W boson production and decay processes. Factorizing the collinear singularity associated with initial state photon radiation into the parton distribution functions, we find that initial state corrections have a significantly smaller effect than final state radiative corrections. We study in detail the effect of electroweak radiative corrections on a number of interesting observables: the W transverse mass distribution, the W to Z transverse mass ratio, the charge asymmetry of leptons in W→l decays, as well as the W production cross section and the W to Z cross section ratio. We also investigate how experimental lepton identification requirements change the effect of the electroweak corrections.

The O(α) radiative corrections to the process p p (−) → γ * , Z → ℓ + ℓ − (ℓ = e, µ) are calculated. Factorizing the collinear singularity associated with initial state photon bremsstrahlung into the parton distribution functions, we find that initial state corrections have a much smaller effect than final state radiative corrections. Due to mass singular logarithmic terms associated with photons emitted collinear with one of the final state leptons, QED radiative corrections strongly affect the shape of the di-lepton invariant mass distribution, the lepton transverse momentum spectrum, and the forward backward asymmetry, A F B . They lead to a sizeable shift in the Z boson mass extracted from data, decrease the di-lepton cross section by up to 10%, and increase the integrated forward backward asymmetry in the Z peak region by about 7% at the Tevatron. We also investigate how experimental lepton identification requirements modify the effect of the QED corrections, and study the prospects for a high precision measurement of sin 2 θ lept ef f using the forward backward asymmetry at the Large Hadron Collider (LHC).

Standard parton distribution function sets do not have rigorously quantified uncertainties. In recent years it has become apparent that these uncertainties play an important role in the interpretation of hadron collider data. In this paper, using the framework of statistical inference, we illustrate a technique that can be used to efficiently propagate the uncertainties to new observables, assess the compatibility of new data with an initial fit, and, in case the compatibility is good, include the new data in the fit.

Methods for measuring the W-boson properties at hadron colliders are discussed. It is demonstrated that the ratio between the W-and Z-boson observables can be reliably calculated using fixed order perturbative QCD, even when the individual W-and Z-boson observables are not. Hence, by using a measured Z-boson observable and the perturbative calculation of the ratio of the W-over Z-boson observable, we can accurately predict the W-boson observable. The use of the ratio reduces both the experimental and theoretical systematic uncertainties substantially. Compared to the currently used methods it might, at high luminosity, result in a smaller overall uncertainty on the measured W-boson mass and width. ͓S0556-2821͑98͒00509-8͔

We extend the phase space slicing method of Giele, Glover and Kosower for performing next-to-leading order jet cross section calculations in two important ways: we show how to include fragmentation functions and how to include massive particles. These extensions allow the application of this method not just to jet cross sections but also to cross sections in which a particular final state particle, including a D or B-meson, is tagged.

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Measurements of the kinematic distributions of J /ψ mesons produced in p-C, p-Ti and p-W collisions at √ s = 41.6 GeV in the Feynman-x region −0.34 < x F < 0.14 and for transverse momentum up to p T = 5.4 GeV/c are presented. The x F and p T dependencies of the nuclear suppression parameter, α, are also given. The results are based on 2.4 × 10 5 J /ψ mesons reconstructed in both the e + e − and μ + μ − decay channels. The data have been collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The measurement explores the negative region of x F for the first time. The average value of α in the measured x F region is 0.981 ± 0.015. The data suggest that the strong nuclear suppression of J /ψ production previously observed at high x F turns into an enhancement at negative x F .

Some results of a calculation of electroweak radiative corrections to W and Z boson production in hadronic collisions are presented.a Talk given by U