Perturbative fragmentation

Abstract

The Berger model of perturbative fragmentation of quarks to pions is improved by providing an absolute normalization and keeping all terms in a (1-z) expansion, which makes the calculation valid at all values of fractional pion momentum z. We also replace the nonrelativistic wave function of a loosely bound pion by the more realistic procedure of projecting to the light-cone pion wave function, which in turn is taken from well known models. The full calculation does not confirm the (1-z)^2 behavior of the fragmentation function (FF) predicted in for $z>0.5$, and only works at very large z>0.95, where it is in reasonable agreement with phenomenological FFs. Otherwise, we observe quite a different z-dependence which grossly underestimates data at smaller z. The disagreement is reduced after the addition of pions from decays of light vector mesons, but still remains considerable. The process dependent higher twist terms are also calculated exactly and found to be important at large z and/or pT.

10 pages, 8 figures

References in corpus (8)

• Global analysis of fragmentation functions for pions and kaons and their uncertainties
• Testing the Universality of Fragmentation Functions
• Pion and Kaon Production in $e^{+}{e}^{-}$ and $ep$ Collisions at Next-to-Leading Order
• Nuclear Hadronization: Within or Without?
• Tagging the pion quark structure in QCD
• Evidences for two scales in hadrons
• Towards the theory of coherent hard dijet production on hadrons and nuclei
• Higher Twist Effects in Deep Inelastic Scattering on Nuclei

Cited by in corpus (6)

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• Transverse Momentum Broadening in Semi-inclusive DIS on Nuclei
• Quantum-mechanical description of in-medium fragmentation
• A heuristic description of high-pT hadron production in heavy ion collisions
• Distinctive features of hadronizing heavy quarks
• Quenching of high-pT hadrons: a non-energy-loss scenario