498 research outputs found

    Direct Calculations of the Odderon Intercept in the Perturbative QCD

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    The odderon intercept is calculated directly, from its expression via an average energy of the odderon Hamiltonian, using both trial wave functions in the variational approach and the wave function recently constructed by R.A.Janik and J.Wosiek. The results confirm their reported value for the energy. The odderon intercept is calculated directly, from its expression via an average energy of the odderon Hamiltonian, using both trial wave functions in the variational approach and the wave function recently constructed by R.A.Janik and J.Wosiek.The results confirm their reported value for the energy. Variational calculations give energies some 30% higher. However they also predict the odderon intercept to be quite close to unity. In fact, for realistic values of αs\alpha_s, the intercept calculated variationally is at most 2% lower than the exact one: 0.94 instead of 0.96. It is also found that the solution for q3=0q_3=0 does not belong to the odderon spectrum. The diffusion parameter is found to be of the order 0.6.Comment: 20 page

    A simple recipe to detect possible C-Odd effects in high energy pˉp\bar p p and pppp

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    We provide a theorem to suggest that t=0t=0 data may already be sufficient to detect possible asymptotic C-odd (Odderon) contributions. This can be done by comparing pˉp\bar p p and pppp t=0t=0 observables such as total cross sections, forward angular distributions and ratios of real to imaginary forward amplitudes for which well defined model independent correlations {must} exist which could already show up at RHIC energy but definitely at LHC energies.Comment: 10 pages in TeX, no figur

    Calculation of the real part of the nuclear amplitude at high s and small t from the Coulomb amplitude

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    A new method for the determination of the real part of the elastic scattering amplitude is examined for high energy proton-proton at small momentum transfer. This method allows us to decrease the number of model assumptions, to obtain the real part in a narrow region of momentum transfer and to test different models. The possible non-exponential behavior of the real part was found on the base of the analysis of the ISR experimental data.Comment: 5 pages, 3 figures, Talk on XIth International Conference on Elastic and Diffractive Scatterin

    The Two-Component Non-Perturbative Pomeron and the G-Universality

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    In this communication we present a generalization of the Donnachie-Landshoff model inspired by the recent discovery of a 2-component Pomeron in LLA-QCD by Bartels, Lipatov and Vacca. In particular, we explore a new property, not present in the usual Regge theory - the G-Universality - which signifies the independence of one of the Pomeron components on the nature of the initial and final hadrons. The best description of all the forward hadron-hadron, gamma- gamma and gamma-proton data is obtained when G-universailty is imposed. Moreover, the maximal (ln)**2 behaviour of the hadron amplitude, first established by Heisenberg, is clearly favoured by the data.Comment: 5 pages, 2 tables, talk at the International Workshop on Diffraction in High-Energy Physics "Diffraction 2000", Cetraro, Italy, September 2-7, 200

    Nucleon Structure and High Energy Scattering

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    If the pomeron is generated by a two gluon exchange there is no a priori reason for a drastic suppression of three gluon exchange with negative parity and charge parity. This would lead to an unacceptably large difference between ppp\,p and ppˉp\, \bar{p} scattering. It is shown that a natural suppression of the CC=PP=--1 contribution to high energy scattering is given by a cluster structure of the nucleon.Comment: 10 pages, epsf.sty and a4wide.sty, 8 eps figs included complete PS-file (with all figs) available at: http://www.thphys.uni-heidelberg.de/~rueter

    A Possible Two-Component Structure of the Non-Perturbative Pomeron

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    We propose a QCD-inspired two-component Pomeron form which gives an excellent description of the proton-proton, pi-proton, kaon-proton, gamma-proton and gamma-gamma total cross sections. Our fit has a better CHI2/dof for a smaller number of parameters as compared with the PDG fit. Our 2-Pomeron form is fully compatible with weak Regge exchange-degeneracy, universality, Regge factorization and the generalized vector dominance model

    How can the Odderon be detected at RHIC and LHC

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    The Odderon remains an elusive object, 33 years after its invention. The Odderon is now a fundamental object in QCD and CGC and it has to be found experimentally if QCD and CGC are right. In the present paper, we show how to find it at RHIC and LHC. The most spectacular signature of the Odderon is the predicted difference between the differential cross-sections for proton-proton and antiproton-proton at high s and moderate t. The experiment can be done by using the STAR detector at RHIC and by combining these future data with the already present UA4/2 data. The Odderon could also be found by ATLAS exeperiment at LHC by performing a high-precision measurement of the real part of the hadron elastic scattering amplitude at small t.Comment: 14 pages, 16 figures, two typographical errors corrected and acknowledgments adde

    Analytic Amplitude Models for Forward Scattering

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    We report on fits of a large class of analytic amplitude models for forward scattering against the comprehensive data for all available reactions. To differentiate the goodness of the fits of many possible parametrizations to a large sample of data, we developed and used a set of quantitative indicators measuring statistical quality of the fits over and beyond the typical criterion of the X2/dof\Chi^2 /dof. These indicators favor models with a universal log2s log^2 s Pomeron term, which enables one to extend the fit down to s=4\sqrt s = 4 GeV.Comment: 13 pages, COMPETE Collaboration, talk presented at the 9th International Conference (Blois Workshop) on Elastic and Diffractive Scatterin

    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

    Analytic Amplitudes for Hadronic Forward Scattering : COMPETE Update

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    We consider several classes of analytic parametrizations of hadronic scattering amplitudes, and compare their predictions to all available forward data in hadron-hadron, gamma-p and gamma-gamma reactions. Although these parametrizations are very close for SQRTs larger than 9 GeV, it turns out that they differ markedly at low energy, where a universal Pomeron term like ln**2 s enables one to extend the fit down to SQRTs equal to 4 GeV. We present predictions on the total cross sections and on the ratio of the real part to the imaginary part of the elastic amplitude (RHO parameter) for present and future pp and antipp colliders, and on total cross sections for gamma-p into hadrons at cosmic-ray energies and for gamma-gamma into hadrons up to SQRTs equal to 1 TeV.Comment: 3 pages, 3 tables. To be published in the Proceedings of the 31st International Conference on High Energy Physics (ICHEP 2002), Amsterdam, The Netherlands, 24-31 July 200
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