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[en] The D0 and CDF Collaborations measure boson pair production including Wγ, WW, WZ, ZZ and Zγ production in p anti p collisions at √s = 1800 GeV. New results, from direct measurements, are described including Wγ, WW, and Zγ production cross sections and limits on non-Standard Model triple gauge boson couplings. The limits on anomalous WWγ, WWZ, Zγγ and ZZγ couplings are the most restrictive available. Prospects for Run II are discussed
[en] This dissertation presents a direct measurement of the W boson mass (MW) and decay width (ΛW) in 1 fb-1 of W → eν collider data at D0 using a novel method to model the hadronic recoil. The mass is extracted from fits to the transverse mass MT, pT(e), and ET distributions. The width is extracted from fits to the tail of the MT distribution. The electron energy measurement is simulated using a parameterized model, and the recoil is modeled using a new technique by which Z recoils are chosen from a data library to match the pT and direction of each generated W boson. We measure the the W boson mass to be MW = 80.4035 ± 0.024(stat) ± 0.039(syst) from the MT, MW = 80.4165 ± 0.027(stat) ± 0.038(syst) from the pT(e), and MW = 80.4025 ± 0.023(stat) ± 0.043(syst) from the ET distributions. ΛW is measured to be ΛW = 2.025 ± 0.038(stat) ± 0.061(syst) GeV.
[en] The W-boson production at the LHC results in an excess of positive over negative lepton candidates. In the framework of the top pair cross section measurement at the ATLAS experiment with 35 pb-1, a new data-driven method based on this charge asymmetry has been implemented to estimate the W-production in association with jets. An overview of the asymmetry is initially presented and the data-driven method is then explained in details. The W-charge asymmetry technique results in a good evaluation of the W-production but suffers from a high statistical uncertainty, which can be reduced when the LHC collects more data.
[en] W and Z boson production has been investigated by the ATLAS Collaboration in proton-proton collisions at √s = 7 TeV. New preliminary precision measurements of the inclusive Dell-Yan cross sections based on the complete data statistics collected in 2010, corresponding to a luminosity of about 35 pb-1, are presented, with particular emphasis on the muon decay channels. The accurate control on experimental systematic uncertainties, at the percent level, shows advanced understanding of the muon trigger and reconstruction achieved after the first year of data taking at the LHC. The measured W+-and Z/γ* cross sections, and their ratios, are in agreement with next-to-next-to-leading-order (NNLO) QCD calculations and start to be sensitive to the choice of the parton distribution functions.
[en] The measurement of the mass of the W boson is one of the prime goals of the Tevatron experiments. In this contribution, a review is given of the most recent determinations of the W boson mass (mW) at the Tevatron. The combined Tevatron result, mW = 80.420 ± 0.031 GeV, is now more precise than the combined LEP result, leading to a world average value of mW = 80.399 ± 0.023 GeV.
[en] This dissertation describes an alternative method of measuring the W boson mass in D0 experiment. Instead of extracting MW from the fitting of W → eν fast Monte Carlo simulations to W → eν data as in the standard method, we make the direct fit of transverse mass between W → eν data and Z → ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (MW/MZ). Given the precisely measured Z boson mass, W mass is directly fitted from W → eν and Z → ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb-1 D0 Run IIa dataset, ratio method gives MW = 80435 ± 43(stat) ± 26(sys) MeV.
[en] The authors investigate the possibility to draw conclusions on the sign of the spin-dependent gluon distribution, ΔG (x, Q2), from existing polarized DIS data. The spin-dependent parton distributions Δ uv, Δ dv, Δ u-bar, Δ d-bar, Δ s and Δ G are constructed in the framework of a phenomenological procedure utilizing some assumptions on signs of valence and sea parton distributions and taking into account the axial gluon anomaly. Results on integral quark contributions to the proton spin, Δ u-tilde, Δ d-tilde, and Δ s-tilde, are used as input. Their predictions for x- and Q2-dependencies of the polarized proton and neutron structure functions, g1p and g1n, are compared to experimental data. It is shown that the neutron structure function, g1n, is especially sensitive to the sign of Δ G (x, Q2). The result of their analysis strongly supports the conclusion that this sign should be positive
[en] The most recent measurements of the trilinear gauge boson couplings from the diboson production at the D0 experiment has been presented. The analyzed final states are Zγ → ννγ, WW → lνl(prime)ν, and WW+WZ → lνjj. We also present results obtained combining all final states involving the W boson. These results represent the most stringent limits set to date at the hadron collider
[en] In this report it is described the measurement of the W→lν production cross-section in proton-proton collision at √s=7TeV with the ATLAS detector. The measurement of the lepton charge asymmetry is also reported. Results are based on data corresponding to an integrated luminosity of approximately 315 nb-1.