Parton fragmentation in the vacuum and in the medium
S. Albino, F. Anulli, F. Arleo, D. Besson, W. Brooks, B. Buschbeck, M. Cacciari, E. Christova, G. Corcella, D. d'Enterria, J. Dolejsi, S. Domdey, M. Estienne, K. Hamacher, M. Heinz, K. Hicks, D. Kettler, S. Kumano, S. -O. Moch, V. Muccifora, S. Pacetti, R. Perez-Ramos, H. -J. Pirner, A. Pronko, M. Radici, J. Rak, C. Roland, G. Rudolph, Z. Rurikova, C. A. Salgado, S. Sapeta, D. H. Saxon, R. Seidl, R. Seuster, M. Stratmann, M. J. Tannenbaum, M. Tasevsky, T. Trainor, D. Traynor, M. Werlen, C. Zhou
TL;DR
These mini-proceedings synthesize the status of parton fragmentation in both vacuum and medium environments, spanning theoretical frameworks such as global fragmentation-function analyses and NNLO time-like splitting, and extensive experimental data from $e^+e^-$, DIS, and hadron colliders. They cover fragmentation in cold nuclear matter via nuclear DIS and the space-time evolution of hadronization, as well as medium-modified fragmentation in hot QCD matter through jet quenching and jet-based measurements at RHIC and the LHC, including gamma-jet tagging. Together, they illuminate how fragmentation functions constrain perturbative calculations, test QCD in extreme environments, and guide future LHC programs such as gamma-jet and full-jet fragmentation studies. The discussions emphasize the need for precise FF uncertainties, improved interfaces for comparing sets, and robust modeling of medium effects on fragmentation to connect theory with forthcoming high-energy nuclear data.
Abstract
We present the mini-proceedings of the workshop on ``Parton fragmentation in the vacuum and in the medium'' held at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*, Trento) in February 2008. The workshop gathered both theorists and experimentalists to discuss the current status of investigations of quark and gluon fragmentation into hadrons at different accelerator facilities (LEP, B-factories, JLab, HERA, RHIC, and Tevatron) as well as preparations for extension of these studies at the LHC. The main physics topics covered were: (i) light-quark and gluon fragmentation in the vacuum including theoretical (global fits analyses and MLLA) and experimental (data from e+e-, p-p, e-p collisions) aspects, (ii) strange and heavy-quark fragmentation, (iii) parton fragmentation in cold QCD matter (nuclear DIS), and (iv) medium-modified fragmentation in hot and dense QCD matter (high-energy nucleus-nucleus collisions). These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.