Fragmentation and Hadronization

TL;DR

Webber surveys experimental and theoretical progress in jet fragmentation and hadronization, distinguishing fragmentation (factorization-based inclusive spectra) from non-perturbative hadronization. It covers DGLAP evolution, small-x resummation (MLLA), and the need for higher-order coefficient functions; it reviews hadronization models (cluster and string) and their performance against Z0 decay data, including baryon-production challenges. It then synthesizes measurements of quark versus gluon jets, current versus target fragmentation in DIS, heavy-quark fragmentation, Bose-Einstein correlations, and WW fragmentation, highlighting agreements and tensions with perturbative and non-perturbative pictures. The work emphasizes the interplay between perturbative evolution and non-perturbative hadronization, the extraction of color-factor ratios, and the ongoing search for inter-W effects.

Abstract

Experimental data, theoretical ideas and models concerning jet fragmentation and the hadronization process are reviewed, concentrating on the following topics: factorization and small-x resummation of fragmentation functions, hadronization models, single-particle yields and spectra in Z decay, comparisons between quark and gluon jets, current and target fragmentation in deep inelastic scattering, heavy quark fragmentation, Bose-Einstein correlations and WW fragmentation.

Figures (26)

• Figure 1: Factorization structure of $e^+e^-\to hX$.
• Figure 2: Cluster and string hadronization models.
• Figure 5: Particle yields in Z$^0$ decay.
• Figure 6: Particle yields in $e^+e^-$ annihilation.
• Figure 7: Low-$x$ fragmentation in $e^+e^-$ annihilation.