184 research outputs found

    Completing the hadronic Higgs boson decay at order αs4\alpha_s^4

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    We compute four-loop corrections to the hadronic decay of the Standard Model Higgs boson which are induced by effective couplings to bottom quarks and gluons, mediated by the top quark. Our numerical results are comparable in size to the purely massless contributions which have been known for a few years. The results presented in this paper complete the order αs4\alpha_s^4 corrections to the hadronic Higgs boson decay.Comment: 15 pages, 2 figure

    Hadronic Higgs boson decay at order αs4\alpha_s^4 and αs5\alpha_s^5

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    We compute corrections to the decay of the Standard Model Higgs boson to hadrons, to the fourth order in the strong coupling constant αs\alpha_s. We use an effective theory in which the Higgs boson couples directly to bottom quarks and to gluons, via top quark--mediated effective couplings. Numerically, our results are of a comparable size to the previously-known "massless" contributions and complete the order αs4\alpha_s^4 corrections to the hadronic decay of the Higgs boson. In these proceedings we also provide an independent cross check of the gluonic Higgs boson decay at order αs5\alpha_s^5.Comment: 6 pages, 0 figures. Contribution to the proceedings of the XXV International Workshop on Deep-Inelastic Scattering and Related Topics (DIS2017), 3-7 April 2017, University of Birmingham, UK. V2: Reference adde

    Top Quark Mass Effects in Higgs and Z Boson Pair Production and Higgs Boson Decays

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    (g−2)μ(g-2)_\mu at four loops in QED

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    We review the four-loop QED corrections to the anomalous magnetic moment of the muon. The fermionic contributions with closed electron and tau contributions are discussed. Furthermore, we report on a new independent calculation of the universal four-loop contribution and compare with existing results.Comment: 6 pages, Contribution to the proceedings of the International workshop on e+e- collisions from Phi to Psi 2017, v2: references adde

    MS‾\overline{\rm MS}-on-shell quark mass relation up to four loops in QCD and a general SU(N)(N) gauge group

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    In this paper we compute the relation between heavy quark masses defined in the modified minimal subtraction and on-shell scheme. Detailed results are presented for all coefficients of the SU(Nc)(N_c) colour factors. The reduction of the four-loop on-shell integrals is performed for a general QCD gauge parameter. Some of the about 380 master integrals are computed analytically, others with high numerical precision based on Mellin-Barnes representations, and the rest numerically with the help of {\tt FIESTA}. We discuss in detail the precise numerical evaluation of the four-loop master integrals. Updated relations between various short-distance masses and the MS‾\overline{\rm MS} quark mass to next-to-next-to-next-to-leading order accuracy are provided for the charm, bottom and top quark. We discuss the dependence on the renormalization and factorization scale.Comment: 53 pages, 11 figures, v2: minor changes, references added, corresponds to published versio

    Completing the hadronic Higgs boson decay at order α4s\frac{4}{s}

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    We compute four-loop corrections to the hadronic decay of the Standard Model Higgs boson which are induced by effective couplings to bottom quarks and gluons, mediated by the top quark. Our numerical results are comparable in size to the purely massless contributions which have been known for a few years. The results presented in this paper complete the order α4s\frac{4}{s} corrections to the hadronic Higgs boson decay

    gg→ZZgg\to ZZ: analytic two-loop results for the low- and high-energy regions

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    We compute next-to-leading order virtual two-loop corrections to the process gg→ZZgg\to ZZ in the low- and high-energy limits, considering the contributions with virtual top quarks. Analytic results for all 20 form factors are presented including expansion terms up to 1/mt121/m_t^{12} and mt32m_t^{32}. We use a Pad\'e approximation procedure to extend the radius of convergence of the high-energy expansion and apply this approach to the fini\ te virtual next-to-leading order corrections.Comment: 31 page

    Double Higgs boson production at NLO in the high-energy limit: complete analytic results

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    We compute the NLO virtual corrections to the partonic cross section of gg→HHgg\to HH, in the high energy limit. Finite Higgs boson mass effects are taken into account via an expansion which is shown to converge quickly. We obtain analytic results for the next-to-leading order form factors which can be used to compute the cross section. The method used for the calculation of the (non-planar) master integrals is described in detail and explicit results are presented.Comment: 26 pages, v2: minor corrections, references added, published versio

    Double-Higgs boson production in the high-energy limit: planar master integrals

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    We consider the virtual corrections to the process gg→HHgg\to HH at NLO in the high energy limit and compute the corresponding planar master integrals in an expansion for small top quark mass. We provide details on the evaluation of the boundary conditions and present analytic results expressed in terms of harmonic polylogarithms.Comment: 25 page
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