Fragmentation functions are determined for pions, kaons, and nucleons by a global analysis of charged-hadron production data in electron-positron annihilation. The optimum functions are obtained in both leading order (LO) and next-to-leading order (NLO) of alpha_s. It is important that uncertainties of the fragmentation functions are estimated in this work by the Hessian method. We found that the uncertainties are large at small Q^2 and that they are generally reduced in the NLO in comparison with the LO ones. We supply a code for calculating the fragmentation functions and their uncertainties for the pions, kaons, and nucleons at given z and Q^2.
@article{arxiv.hep-ph/0612009,
title = {Determination of fragmentation functions and their uncertainties from e+ + e- -> h + X data},
author = {M. Hirai and S. Kumano and T. -H. Nagai and K. Sudoh},
journal= {arXiv preprint arXiv:hep-ph/0612009},
year = {2008}
}
Comments
4 pages, LaTeX, 5 eps files, to be published in AIP proceedings of the 17th International Spin Physics Symposium (SPIN2006), Oct. 2-7, 2006, Kyoto, Japan