5,734 research outputs found
Modular Invariance and the Odderon
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
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
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
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
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
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
Electrodynamic processes in the ionopause are examined as well as the structure of the induced magnetosphere
The World as a Hologram
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
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
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
, 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 
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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