7,272 research outputs found

    Electroweak Corrections

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    The test of the electroweak corrections has played a major role in providing evidence for the gauge and the Higgs sectors of the Standard Model. At the same time the consideration of the electroweak corrections has given significant indirect information on the masses of the top and the Higgs boson before their discoveries and important orientation/constraints on the searches for new physics, still highly valuable in the present situation.The progression of these contributions is reviewed.Comment: 14 pages, 3 figures, a contribution to "The Standard Theory up to the Higgs discovery - 60 years of CERN

    Supersymmetric Electroweak Corrections to Single Top Quark Production at the Fermilab Tevatron

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    We have calculated the O(αewMt2/MW2)O(\alpha_{ew} M_t^2/M_W^2) supersymmetric electroweak corrections to single top quark production via qqˉ′→tbˉq\bar q' \to t\bar b at the Fermilab Tevatron in the minimal supersymmetric model. The supersymmetric electroweak corrections to the cross section are a few percent for tanβ>1tan \beta> 1, and can exceed 10% for tanβ<1tan\beta<1. The combined effects of SUSY electroweak corrections and the Yukawa corrections can exceed 10% for favorable parameter values, which might be observable at a high-luminosity Tevatron.Comment: 13 pages, 4 figures available at reques

    NLO electroweak corrections to off-shell top-antitop production with leptonic decays at the LHC

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    For the first time the next-to-leading-order electroweak corrections to the full off-shell production of two top quarks that decay leptonically are presented. This calculation includes all off-shell, non-resonant, and interference effects for the 6-particle phase space. While the electroweak corrections are below one per cent for the integrated cross section, they reach up to 15% in the high-transverse-momentum region of distributions. To support the results of the complete one-loop calculation, we have in addition evaluated the electroweak corrections in two different pole approximations, one requiring two on-shell top quarks and one featuring two on-shell W bosons. While the former deviates by up to 10% from the full calculation for certain distributions, the latter provides a very good description for most observables. The increased centre-of-mass energy of the LHC makes the inclusion of electroweak corrections extremely relevant as they are particularly large in the Sudakov regime where new physics is expected to be probed.Comment: 33 pages,23 eps-figures. Matches the published version. Typo fixed in equations (2.18) and (2.19

    Combining QCD and electroweak corrections to dilepton production in FEWZ

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    We combine the next-to-next-to-leading order (NNLO) QCD corrections to lepton-pair production through the Drell-Yan mechanism with the next-to-leading order (NLO) electroweak corrections within the framework of the FEWZ simulation code. Control over both sources of higher-order contributions is necessary for measurements where percent-level theoretical predictions are crucial, and in phase-space regions where the NLO electroweak corrections grow large. The inclusion of both corrections in a single simulation code eliminates the need to separately incorporate such effects as final-state radiation and electroweak Sudakov logarithms when comparing many experimental results to theory. We recalculate the NLO electroweak corrections in the complex-mass scheme for both massless and massive final-state leptons, and modify the QCD corrections in the original FEWZ code to maintain consistency with the complex-mass scheme to the lowest order. We present phenomenological results for LHC studies that include both NNLO QCD and NLO electroweak corrections. In addition, we study several interesting kinematics features induced by experimental cuts in the distribution of photon radiation at the LHC.Comment: 21 pages, 13 figure

    NLO corrections to WWZ and ZZZ production at the ILC

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    We calculate the full one-loop electroweak corrections to tri-boson production (ZZZ and WWZ) at the ILC. This is important to understand the Standard Model (SM) gauge quartic couplings which can be a window on the mechanism of spontaneous symmetry breaking. We find that even after subtracting the leading QED corrections, the electroweak corrections can still be large especially as the energy increases.Comment: 7 pages, proceedings of the 3rd CPP Workshop, September 23-25, 2010, KEK Tsukuba Japa

    Electroweak Corrections at High Energies

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    We present a survey of the most abundant processes at the LHC for sensitivity to electroweak corrections at \sqrt{s} = 8, 14, 33, and 100 TeV proton-proton collision energies. The processes studied are pp -> dijet, inclusive W and Z, W/Z+jets, and WW. In each case we compare the experimental uncertainty in the highest kinematic regions of interest with the relative magnitude of electroweak corrections and fixed-order \alpha_S calculations.Comment: Contribution to the Snowmass-2013 report of the QCD Working Group. 15 pages, 14 figures, 5 tables. Version 2: Added a new section 4A and updated the author list, acknowledgements, and references. Version 3: Added a new reference Ref.[36

    Nonfactorizable QCD and Electroweak Corrections to the Hadronic Z Boson Decay Rate

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    We present an analysis of two-loop mixed QCD and electroweak corrections to the decay of the Z boson into light quarks. We find that the naive factorization of QCD and electroweak corrections does not describe correctly the two-loop effects. The nonfactorizable corrections shift the width of the Z boson by approximately -0.55(3) MeV and increase the central value of the strong coupling constant determined at LEP by 0.001.Comment: 9 pages, Revte
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