Fragmentation into b hadrons

The fragmentation process of b quarks into b hadrons, produced in Z decays or pp collisions, cannot be fully described perturbatively but relies on phenomenological models. To test and tune the parameters of these models, precise experimental measurements have to be performed. Furthermore, properties of the b hadron production process affect many analyses dealing with decays of b hadrons. Thus, precise knowledge of the fragmentation properties allows more accurate measurements in this field. New results for the b fragmentation function and b hadron production fractions have been submitted to this conference and will be summarised in this article. Combined results for b hadron production rates will also be given. (8 refs).