125 research outputs found

    BFKL at next-to-leading order

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    This is a summary of the contributions on the next-to-leading order corrections to the BFKL equation which were presented to the `Small-x and Diffraction' working group at the 1998 Durham Workshop on HERA Physics.Comment: 6 pages, 2 figure

    Baxter Equation for the QCD Odderon

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    The Hamiltonian derived by Bartels, Kwiecinski and Praszalowicz for the study of high-energy QCD in the generalized logarithmic approximation was found to correspond to the Hamiltonian of an integrable XXXXXX spin chain. We study the odderon Hamiltonian corresponding to three sites by means of the Bethe Ansatz approach. We rewrite the Baxter equation, and consequently the Bethe Ansatz equations, as a linear triangular system. We derive a new expression for the eigenvectors and the eigenvalues, and discuss the quantization of the conserved quantities.Comment: 14 pages, latex file, one figur

    Resummation of double logarithms in electroweak high energy processes

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    At future linear e+ee^+e^- collider experiments in the TeV range, Sudakov double logarithms originating from massive boson exchange can lead to significant corrections to the cross sections of the observable processes. These effects are important for the high precision objectives of the Next Linear Collider. We use the infrared evolution equation, based on a gauge invariant dispersive method, to obtain double logarithmic asymptotics of scattering amplitudes and discuss how it can be applied, in the case of broken gauge symmetry, to the Standard Model of electroweak processes. We discuss the double logarithmic effects to both non-radiative processes and to processes accompanied by soft gauge boson emission. In all cases the Sudakov double logarithms are found to exponentiate. We also discuss double logarithmic effects of a non-Sudakov type which appear in Regge-like processes.Comment: 26 pages, 3 figures, Latex2

    Near-integrability and confinement for high-energy hadron-hadron collisions

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    We investigate an effective Hamiltonian for QCD at large s, in which longitudinal gauge degrees of freedom are suppressed, but not eliminated. In an axial gauge the effective field theory is a set of coupled (1+1)-dimensional principal-chiral models, which are completely integrable. The confinement problem is solvable in this context, and we find the longitudinal and transverse string tensions with techniques already used for a similar Hamiltonian in (2+1)-dimensions. We find some a posteriori justification for the effective Hamiltonian as an eikonal approximation. Hadrons in this approximation consist of partons, which are quarks and soliton-like excitations of the sigma models. Diffractive hadron-hadron scattering appears primarily due to exchange of longitudinal flux between partons.Comment: Typographical errors corrected, language improved, reference adde

    Exclusive diffractive production of real photons and vector mesons in a factorized Regge-pole model with non-linear Pomeron trajectory

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    Exclusive diffractive production of real photons and vector mesons in ep collisions has been studied at HERA in a wide kinematic range. Here we present and discuss a Regge-type model of real photon production (Deeply Virtual Compton Scattering), as well as production of vector mesons (VMP) treated on the same footing by using an extension of a factorized Regge-pole model proposed earlier. The model has been fitted to the HERA data. Despite the very small number of the free parameters, the model gives a satisfactory description of the experimental data, both for the total cross section as a function of the photon virtuality Q2 or the energy W in the center of mass of the gamma\star-p system, and the differential cross sections as a function of the squared four-momentum transfer t with fixed Q2 and W.Comment: 34 pages, 82 figures accepted by Physical Review

    Effective Regge QCD

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    A new framework for a high energy limit of quantum gauge field theories is introduced. Its potency is illustrated on a new derivation of the reggeization of the gluon.Comment: Latex, 9 pages + 2 figures as PS-file, extended version, to appear in Phys. Rev. Let

    Disperse composition of dust in hydro-metallurgical production of copper

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    The article describes the main technological processes of pyroand hydrometallurgy of copper. Air sampling of the working area was carried out in accordance with PNDF 13: 2: 3.71-11. A brief comparative characteristic of the dispersed dust composition is given.В статье рассмотрены основные технологические процессы пиро- и гидрометаллургии меди. Проведен отбор проб воздуха рабочей зоны в соответствии с ПНДФ 13:2:3.71-11. Дана краткая сравнительная характеристика дисперсного состава пыли

    Solution of the Odderon Problem

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    The intercept of the odderon trajectory is derived, by finding the spectrum of the second integral of motion of the three reggeon system in high energy QCD. When combined with earlier solution of the appropriate Baxter equation, this leads to the determination of the low lying states of that system. In particular, the energy of the lowest state gives the intercept of the odderon alpha_O(0)=1-0.2472 alpha_s N_c/pi.Comment: 11 pages, 2 Postscript figure

    Infrared safety of impact factors for colourless particle interactions

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    We demonstrate, to next-to-leading order accuracy, the cancellation of the infrared singularities in the impact factors which arise in the QCD description of high energy processes A + B -> A' + B' of colourless particles. We study the example where A is a virtual photon in detail, but show that the result is true in general.Comment: 31 pages latex including 10 figure

    Virtual Next-to-Leading Corrections to the Impact Factors in the High-Energy Limit

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    We compute the virtual next-to-leading corrections to the impact factors or off-shell coefficient functions in the high-energy limit. When combined with the known real corrections, these results will provide the complete NLO corrections to the impact factors, which are necessary to use the BFKL resummation at NLL for jet production at both lepton-hadron and hadron-hadron colliders.Comment: LaTeX, 23 page
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