Fragmentation Phenomenology

摘要

Some of the virtues and the limitations of the existing QCD Monte-Carlo models for e exp + e exp - annihilation are discussed. In particular, the question of whether the uncalculable fragmentation phase prohibits an accurate determination of the size of the strong interaction coupling constant, alpha /sub s/, at present energies is addressed. It is argued that, although the Monte-Carlo models are good for some things, they are not particularly useful in determining alpha /sub s/. The coupling alpha /sub s/ is best determined by directly comparing e exp + e exp - data with second order analytic calculations and a prototype analysis is presented which yields lambda /sub ms/ approx. = 0.2 +- 0.1 Ge. Monte-Carlo models that do not rely on the limited transverse momentum jet parameterization of Field and Feynman are examined and a dynamical mechanism for the production of baryons in e exp + e exp - annihilations both on and off the Upsilon resonance is presented. 36 references. (ERA citation 09:015326)