Decisive role of fragmentation functions in hard hadron production

Phys Rev Lett. 2002 Dec 30;89(27):272301. doi: 10.1103/PhysRevLett.89.272301. Epub 2002 Dec 16.


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.