Pomeron fan diagrams in perturbative QCD

Within QCD reggeon field theory we study the formation of two subsequent triple pomeron vertices in the process P$\to$PP$\to$PPP. We make use of an earlier investigation ~\cite{Bartels:1999aw} of the six-reggeon amplitude in deep inelastic scattering and show that in the large-$N_c$ limit pomeron fan diagrams emerge with the same triple pomeron vertex in all places. We thus confirm the BK-equation, but we also find additional terms related to the reggeization of the gluon, and we discuss their potential significance. Our analysis also includes the general pomeron $\to$ two odderon vertex: a particular version of this vertex has been included into earlier generalizations the BK equation.Comment: 22 pages, 10 figure

The Farrell-Hsiang method revisited

We present a sufficient condition for groups to satisfy the Farrell-Jones Conjecture in algebraic K-theory and L-theory. The condition is formulated in terms of finite quotients of the group in question and is motivated by work of Farrell-Hsiang.Comment: This version is different from the published version. A number of typos and an incorrect formula for the transfer before Lemma 6.3 pointed out by Holger Reich have been correcte

Solution of Twist-3 Evolution Equation in Double Logarithmic Approximation in QCD

The solution of DGLAP evolution equation for the twist-3 gluon operators is obtained in the Double Logarithmic Approximation of QCD perturbation theory. The method used for the solution is similar to the reggeon field theory. The asymptotics of the twist-3 parton correlation function for the small Bjorken variables $x_B$ is found.Comment: 12 pages, 4 figures, added references and comment

A momentum Space Analysis of the Triple Pomeron Vertex in pQCD

We study properties of the momentum space Triple Pomeron Vertex in perturbative QCD. Particular attention is given to the collinear limit where transverse momenta on one side of the vertex are much larger than on the other side. We also comment on the kernels in nonlinear evolution equations.Comment: Minor misprints corrected. To be published in EPJ

Massive c\bar c g - Calculation in Diffractive DIS and Diffractive D^* - Production at HERA

We calculate the cross section for $c\bar{c}g$-production in diffractive DIS with finite quark masses at zero momentum transfer $t$. The calculation is done in the leading log(1/$x_{P}$) approximation and is valid in the region of high diffractive masses $M$ (small $\beta$). We apply our cross section formula including both $c{\bar c}$- and $c\bar{c}g$ in a Monte Carlo simulation to diffractive $D^{*\pm}$ meson production at HERA. We compare our predictions to results of H1 using three parameterizations for the unintegrated gluon density.Comment: 11 pages, 5 figure

NLO jet production in k_T factorization

We discuss the inclusive production of jets in the central region of rapidity in the context of k_T-factorization at next-to-leading order (NLO). Calculations are performed in the Regge limit making use of the NLO BFKL results. We introduce a jet cone definition and carry out a proper phase--space separation into multi-Regge and quasi-multi-Regge kinematic regions. We discuss two situations: scattering of highly virtual photons, which requires a symmetric energy scale to separate impact factors from the gluon Green's function, and hadron-hadron collisions, where a non-symmetric scale choice is needed.Comment: 7 pages, 1 figure, prepared for the 12th International Conference on Elastic and Diffractive Scattering, DESY, Hamburg, 21-25 May 200