  Fragmentation functions for eta mesons are extracted at next-to-leading order
accuracy of QCD in a global analysis of data taken in electron-positron
annihilation and proton-proton scattering experiments. The obtained
parametrization is in good agreement with all data sets analyzed and can be
utilized, for instance, in future studies of double-spin asymmetries for
single-inclusive eta production. The Lagrange multiplier technique is used to
estimate the uncertainties of the fragmentation functions and to assess the
role of the different data sets in constraining them.
