title: Decisive role of fragmentation functions in hard hadron production.
abstract: It is demonstrated that the fragmentation functions at large momentum fraction play a key role in hard hadron production from relativistic proton-proton collisions. We find that this region of the fragmentation functions is not strongly constrained by the electron-positron data. This freedom can be used (together with the transverse-momentum distribution of partons) to reproduce hard pion-to-proton ratio data in relativistic proton-proton collisions.
authors.affiliation: Center for Nuclear Research, Department of Physics, Kent State University, Kent, OH 44242, USA.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Zhang
authors.forename: George
authors.initials: G
authors.lastname: Fai
authors.forename: Péter
authors.initials: P
authors.lastname: Lévai