arXiv subjects
Publications and source records attributed to C. Ewerz.
2nd workshop on the implications of HERA for LHC physics. Working groups: Parton Density Functions Multi-jet final states and energy flows Heavy quarks (charm and beauty) Diffraction Cosmic Rays Monte Carlos and Tools
Proceedings of the 12th International Conference on Elastic and Diffractive Scattering (Blois Workshop) - Forward Physics and QCD
We present a numerical estimate of the $γ^* γ^*$ total cross section at the designed 500 GeV $e^+e^-$ Linear Collider, based upon the BFKL Pomeron. We find that the event rate is substantial provided electrons scattered under small angles can be detected, and a measurement of this cross section provides an excellent test of the BFKL Pomeron.
In this talk I describe recent progress in investigating the high energy limit of perturbative QCD. I review some of the steps that have been done in the direction of constructing an effective field theory for this limit. I describe some of its building blocks and explain why we expect the effective theory to be a 2+1-dimensional conformal field theory.
We investigate the azimuthal distribution of quark-antiquark jets in DIS diffractive dissociation with large transverse momentum. In this kinematical region the matrix element is expressed in terms of the gluon structure function. For the transverse part of the cross section we find a $\cos(2 ϕ)$-distribution with the maximum at $ϕ= \pm π/2$, i.e.\ the jets prefer a direction perpendicular to the electron plane. This is in contrast to boson gluon fusion where the $q\bar{q}$ jet cross section for transversely polarized bosons peaks at $ϕ=0$ and $ϕ=π$. We discuss the origin of this striking difference and present numerical results relevant for the diffractive dissociation at HERA.
We calculate the cross section for the production of two jets with large transverse momenta $\kf^2$ in DIS diffractive dissociation for both transverse and longitudinally polarized photons. The scale which defines the hardness of the pomeron is found to be $\kf^2\frac{Q^2+M^2}{M^2}$. We present analytic expressions and discuss numerical results relevant for the diffractive dissociation at HERA.