5,734 research outputs found

    Modular Invariance and the Odderon

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    We identify a new symmetry for the equations governing odderon amplitudes, corresponding in the Regge limit of QCD to the exchange of 3 reggeized gluons. The symmetry is a modular invariance with respect to the unique normal subgroup of sl(2,Z) {\,} of index 2. This leads to a natural description of the Hamiltonian and conservation-law operators as acting on the moduli space of elliptic curves with a fixed ``sign'': elliptic curves are identified if they can be transformed into each other by an {\em even} number of Dehn twists.Comment: 9 pages, LaTeX, uses amssym.def for \Bbb 'blackboard math' font

    BFKL Pomeron in string models

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    We consider scattering amplitudes in string models in the Regge limit of high energies and fixed momentum transfers with the use of the unitarity in direct channels. Intermediate states are taken in the multi-Regge kinematics corresponding to the production of resonances with fixed invariant masses and large relative rapidities. In QCD such kinematics leads to the BFKL equation for the Pomeron wave function in the leading logarithmic approximation. We derive a similar equation in the string theory and discuss its properties. The purpose of this investigation is to find a generalization of the BFKL approach to the region of small momentum transfers where non-perturbative corrections to the gluon Regge trajectory and reggeon couplings are essential. The BFKL equation in the string theory contains additional contributions coming from a linear part of the Regge trajectory and from the soft Pomeron singularity appearing already in the tree approximation. In higher dimensions in addition, a non-multi-Regge kinematics corresponding to production of particles with large masses is important. We solve the equation for the Pomeron wave function in the string theory for D=4 and discuss integrability properties of analogous equations for composite states of several reggeised gluons in the multi-colour limit.Comment: 48 pages, 2 figure

    The effective action and the triple Pomeron vertex

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    We study integrations over light-cone momenta in the gauge invariant effective action of high energy QCD. A regularization mechanism which allows for the evaluation of the longitudinal integrations is presented. After a rederivation of the reggeized gluon and the BFKL-equation from the effective action, we study the 1-3 and 2-4 reggeized gluon transition vertex of QCD Reggeon field theory and discuss their connection with the usual triple Pomeron vertex of perturbative QCD.Comment: Talk given at the 3rd International Hadron Structure '09 Conference, Tatranska Strba, Slovakia, 30 Aug - 3 Sep 2009; 4 pages, 16 figure

    Conformal Invariance of Unitarity Corrections

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    We study perturbative unitarity corrections in the generalized leading logarithmic approximation in high energy QCD. It is shown that the corresponding amplitudes with up to six gluons in the t-channel are conformally invariant in impact parameter space. In particular we give a new representation for the two-to-six reggeized gluon vertex in terms of conformally invariant functions. With the help of this representation an interesting regularity in the structure of the two-to-four and the two-to-six transition vertices is found.Comment: 11 page

    Quasi-multi-Regge Processes with a Quark Exchange in the t-channel

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    The QCD amplitudes for particle's production in the quasi-multi-Regge kinematics with a quark exchange in crossing channels are calculated in the Born approximation. In particular they are needed to find next-to-leading corrections to the quark Regge trajectory and to the integral kernel of the Bethe-Salpeter equation for the t-channel partial wave with fermion quantum numbers and a negative signature. The gauge-invariant action for the interaction of the reggeized quarks and gluons with the usual particles is constructed.Comment: LaTeX, 10 page

    Social Interaction in Tax Evasion

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    We analyze the tax evasion problem with social interaction among the taxpayers. If the authority commits to a fixed auditing probability, a positive share of cheating is obtained in equilibrium. This stands in contrast to the existing literature, which yields full compliance of audited taxpayers who are rational and thus do not need to interact. When the authority adjusts the auditing probability every period, cycling in cheating-auditing occurs. Thus, the real life phenomenon of compliance fluctuations is explained within the model rather than by exogenous parameter shifts. Our analysis can also be applied to crime, safety regulations, employment and environmental protection, as well as other compliance problems.tax evasion, learning, social interaction, behavioral rule, compliance

    Numerical modeling of stimulation of induced magnetosphere during interaction of solar wind with the ionosphere of Venus

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    Electrodynamic processes in the ionopause are examined as well as the structure of the induced magnetosphere

    The World as a Hologram

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    According to 't Hooft the combination of quantum mechanics and gravity requires the three dimensional world to be an image of data that can be stored on a two dimensional projection much like a holographic image. The two dimensional description only requires one discrete degree of freedom per Planck area and yet it is rich enough to describe all three dimensional phenomena. After outlining 't Hooft's proposal I give a preliminary informal description of how it may be implemented. One finds a basic requirement that particles must grow in size as their momenta are increased far above the Planck scale. The consequences for high energy particle collisions are described. The phenomena of particle growth with momentum was previously discussed in the context of string theory and was related to information spreading near black hole horizons. The considerations of this paper indicate that the effect is much more rapid at all but the earliest times. In fact the rate of spreading is found to saturate the bound from causality. Finally we consider string theory as a possible realization of 't Hooft's idea. The light front lattice string model of Klebanov and Susskind is reviewed and its similarities with the holographic theory are demonstrated. The agreement between the two requires unproven but plausible assumptions about the nonperturbative behavior of string theory. Very similar ideas to those in this paper have been long held by Charles Thorn.Comment: SU-ITP-94-33, phyzzx, 33 pages and 5 figures (Some typos fixed and one reference added.

    N=4 supersymmetric Yang Mills scattering amplitudes at high energies: the Regge cut contribution

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    We further investigate, in the planar limit of N=4 supersymmetric Yang Mills theories,the high energy Regge behavior of six-point MHV scattering amplitudes. In particular, for the new Regge cut contribution found in our previous paper, we compute in the leading logarithmic approximation (LLA) the energy spectrum of the BFKL equation in the color octet channel, and we calculate explicitly the two loop corrections to the discontinuities of the amplitudes for the transitions 2 to 4 and 3 to 3. We find an explicit solution of the BFKL equation for the octet channel for arbitrary momentum transfers and investigate the intercepts of the Regge singularities in this channel. As an important result we find that the universal collinear and infrared singularities of the BDS formula are not affected by this Regge-cut contribution. Any improvement of the BDS formula should reproduce this cut to all orders in the coupling

    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
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