Eur. Phys. J. C 22, 269-276 (2001)
Fragmentation functions from semi-inclusive DIS pion production and implications for the polarized parton densitiesS. Kretzer1, E. Leader2 and E. Christova3
1 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48823, USA
2 High Energy Physics Group, Imperial College, London, UK
3 Institute of Nuclear Research and Nuclear Energy, Sofia, Bulgaria
(Received: 6 August 2001 / Revised version: 3 October 2001 / Published online: 12 November 2001 - © Springer-Verlag / Società Italiana di Fisica 2001 )
By combining recent HERMES data on semi-inclusive DIS (SIDIS) -production with the singlet fragmentation function , which is well determined from e+e- data, we are able to extract, for the first time, the flavoured fragmentation functions , and without making any assumptions about favoured and unfavoured transitions. Whereas and are very well determined, the accuracy of is limited by the uncertainty in evolving from the Z0 pole down to the SIDIS scale of a few (GeV)2. We discuss how the precision on could be improved. Knowledge of the will permit the extraction of the polarized parton densities from future polarized SIDIS asymmetry measurements. We study the precision that can be expected in such an extraction.
© Società Italiana di Fisica, Springer-Verlag 2001