Hannes Jung

Hard diffractive scattering in high energy ep collisions and the Monte Carlo generator RAPGAP

Abstract The program RAPGAP generates events in ep collisions where the electron is scattered on a pomeron P coupled to the proton p. A gap in rapidity between the fast moving proton and the remaining hadronic system is observed. The program is applicable to photoproduction ( Q 2 ⋍ 0 ) as well as deep inelastic scattering (Q2 > 0). Different types of hard interaction processes such as γ∗ q → q′ and γrg → q q for light and heavy quarks are included. Several options for the parametrisation of the pomeron and its parton density are available within the program. The hadronisation is performed using the LUND string fragmentation model. The Monte Carlo implementation is described and some phenomenological consequences are discussed.

Hadronic final state predictions from CCFM: the hadron-level Monte Carlo generator Cascade

Abstract. We discuss a practical formulation of backward evolution for the CCFM small-x evolution equation and show results from its implementation in the new Monte Carlo event-generator Cascade.

Small x phenomenology: Summary and status

Abstract. The aim of this paper is to summarize the general status of our understanding of small-x physics. It is based on presentations and discussions at an informal meeting on this topic held in Lund, Sweden, in March 2001. This document also marks the founding of an informal collaboration between experimentalists and theoreticians with a special interest in small-x physics. This paper is dedicated to the memory of Bo Andersson, who died unexpectedly from a heart attack on March 4th, 2002.The aim of this paper is to summarize the general status of our understanding of small-x physics. It is based on presentations and discussions at an informal meeting on this topic held in Lund, Sweden, in March 2001. This document also marks the founding of an informal collaboration between experimentalists and theoreticians with a special interest in small-x physics. This paper is dedicated to the memory of Bo Andersson, who died unexpectedly from a heart attack on March 4th, 2002.

The CCFM Monte Carlo generator CASCADE

CASCADE is a full hadron level Monte Carlo event generator for ep, gammap and p (p) over bar processes, which uses the CCFM evolution equation for the initial state cascade in a backward evolution approach supplemented with off-shell matrix elements for die hard scattering. A detailed program description is given, with emphasis on parameters the user wants to change and common block variables which completely specify the generated events.

The CCFM Monte Carlo generator CASCADE Version 2.2.03

Cascade is a full hadron level Monte Carlo event generator for ep, γp and

Transverse momentum dependent (TMD) parton distribution functions: Status and prospects*

p\bar{p}

Small x Phenomenology - summary of the 3rd Lund Small x Workshop in 2004

and pp processes, which uses the CCFM evolution equation for the initial state cascade in a backward evolution approach supplemented with off-shell matrix elements for the hard scattering. A detailed program description is given, with emphasis on parameters the user wants to change and common block variables which completely specify the generated events.

k(t)-factorization and CCFM: The solution for describing the hadronic final states everywhere?

We review transverse momentum dependent (TMD) parton distribution functions, their application to topical issues in high-energy physics phenomenology, and their theoretical connections with QCD resummation, evolution and factorization theorems. We illustrate the use of TMDs via examples of multi-scale problems in hadronic collisions. These include transverse momentum q(T) spectra of Higgs and vector bosons for low q(T), and azimuthal correlations in the production of multiple jets associated with heavy bosons at large jet masses. We discuss computational tools for TMDs, and present the application of a new tool, TMDLIB, to parton density fits and parameterizations.

Transverse momentum dependent gluon density from DIS precision data

A third workshop on small-x physics, within the Small-x Collaboration, was held in Hamburg in May 2004 with the aim of overviewing recent theoretical progress in this area and summarizing the experimental status.

Heavy quark production at the Fermilab Tevatron and DESY ep collider HERA using k(t) factorization with the CCFM evolution approach

The basic ideas of k(t)-factorization and CCFM parton evolution is discussed. The unintegrated gluon densities, obtained from CCFM fits to the proton structure function data at HERA are used to predict hadronic final state cross-sections like jet production at HERA, but also comparisons with recent measurements of heavy quark production at the Tevatron are presented. Finally, the k(t)-factorization approach is applied to Higgs production at high energy hadron-hadron colliders and the transverse momentum spectrum of Higgs production at the LHC is calculated.