The Real Corrections to the Gamma* Impact Factor: First Numerical Results

We have performed analytically the transverse momentum integrations in the real corrections to the longitudinal \gamma^*_L impact factor and carried out numerically the remaining integrations. I outline the analytical integration and present the numerical results: we have performed a numerical test and computed those parts of the impact factor that depend upon the energy scale s_0.Comment: 4 pages, 3 figures, to appear in proceedings of "DIS 2004", XII International Workshop on Deep Inelastic Scattering (April 2004, Strbske Pleso, Slovakia

Properties of a family of n reggeized gluon states in multicolour QCD

A general relation between families of (n+1) gluon and n gluon eigenstates of the BKP evolution kernels in the multicolour limit of QCD is derived. It allows to construct an (n+1) gluon eigenstate if an n gluon eigenstate is known; this solution is Bose symmetric and thus physical for even n. A recently found family of odderon solutions corresponds to the particular case n=2.Comment: 11 pages, 1 figur

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

AGK Cutting Rules and Multiple Scattering in Hadronic Collisions

We discuss the AGK rules for the exchange of an arbitrary number of reggeized gluons in perturbative QCD in the high energy limit. Results include the cancellation of corrections to single jet and double jet inclusive cross sections, both for hard and soft rescattering contributions.Comment: 31 pages, latex, 20 figure

Polarised deep inelastic scattering accompanied by a forward jet as a probe of the ln⁡2(1/x)\ln^2(1/x) resummation

We argue that the production of forward jets in polarised deep inelastic scattering can be a useful tool for probing the double $ln^2(1/x)$ resummation effects which control the polarised deep inelastic scattering for small values of the Bjorken parameter $x$. We solve the corresponding integral equations generating the double $ln^2(1/x)$ resummation and calculate the differential structure function describing the forward jet production in the small $x$ regime which can possibly be probed by the polarised HERA measurements. We show that these structure functions should exhibit the characteristic increase with decreasing $x/x_J$, where $x_J$ denotes the longitudinal momentum fraction of the parent proton carried by a jet, and we quantify this increase.Comment: 13 pages, latex, 5 figure

Higher twists in deep inelastic scattering

We perform an exploratory study of higher twist contributions to deep inelastic scattering. We estimate the size of two major sources of higher twist, namely absorptive corrections and the vector meson dominance (VMD) contribution. We find that they give a sizeable higher twist component of F_2. For example at x = 0.01 it is about 8% (17%) at Q^2 = 10 GeV^2 (4 GeV^2), reaching up to 27% at x = 10^{-4} and Q^2 = 4 GeV^2. At the smaller x value the largest contribution comes from absorptive corrections, while at the larger values of x the VMD term dominates.Comment: The sign of the gluon rescattering twist-4 component has been corrected and the manuscript modified accordingl

BKP states in the inclusive gluon production

Inclusive cross-section for gluon production is calculated by the dispersion technique in the NLO in the perturbative QCD with a large number of colours. The found cross-section coincides with the one derived in the dipole picture. No trace of the BKP states is found.Comment: 30 pages, 17 figures. Appendix with a new observation added. Conclusions changed

Redistribution and Insurance in the German Welfare State

Welfare states redistribute both between individuals reducing annual inequality and over the life-cycle insuring against income risks. But studies measuring redistribution often focus only on a one-year period. Using German SOEP data from 1984 to 2009, long-term inequality over a 20-year period is computed and then decomposed into an inter- and intra-individual component. Results show that annual inequality is higher than long-term inequality, but redistribution is also larger annually. In the long-term, the German welfare state clearly gives priority to insurance over redistribution. This gets even more pronounced at later stages of the life-cycle through the payment of social security pensions.Long-term income inequality, Income redistribution, Social security