2003/05/07 by Carola F. Berger, Berger, Carola F.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0305076
Ph.D. Thesis (Advisor: George Sterman). 22+208pp
openalex publication_date 2003/05/07 · arxiv created 2003/05/18 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In calculations of (semi-) inclusive events within perturbative Quantum Chromodynamics, large logarithmic corrections arise from certain kinematic regions of interest which need to be resummed. When resumming soft gluon effects one encounters quantities built out of eikonal or Wilson lines (path ordered exponentials). In this thesis we develop a simplified method to calculate higher orders of the singular coefficients of parton distribution functions which is based on the exponentiation of cross sections built out of eikonal lines. As an illustration of the method we determine the previously uncalculated fermionic contribution to the three-loop coefficient A^(3). The knowledge of these coefficients is not only important for the study of the parton distribution functions themselves, but also for the resummation of large logarithmic effects due to soft radiation in a variety of cross sections. In the second part of this thesis we study the energy flow pattern of this soft radiation in jet events. We develop the concept of event shape-energy flow correlations that suppress radiation from unobserved "minijets" outside the region of interest and are sensitive primarily to radiation from the highest-energy jets. We give analytical and numerical results at next-to-leading logarithmic order for shape/flow correlations in e+e- dijet events. We conclude by illustrating the application of our formalism to events with hadrons in the initial state, where the shape/flow correlations can be described via matrices in the space of color exchanges.