Theoretical aspects of inclusive light-hadron production

Abstract

We summarize the key results of a recent global analysis of inclusive single-charged-hadron production in high-energy colliding-beam experiments. In the framework of the parton model of quantum chromodynamics at next-to-leading order (NLO), fragmentation functions (FFs) for charged pions, charged kaons and (anti)protons are extracted from the experimental data of e+e− annihilation at the Z-boson resonance and at centre-of-mass energy √s = 29 GeV. This fit also yields a new NLO value for the strong-coupling constant, namely α(5)s(MZ) = 0.1170 ± 0.0073. The scaling violations encoded in the FFs through the Altarelli–Parisi evolution equations are tested by confronting e+e−-annihilation data from DESY DORIS, DESY PETRA and CERN LEP2 with NLO predictions based on these FFs. Comparisons of pp̄ data from CERN Spp̄S and the Fermilab Tevatron, γp data from DESY HERA and γγ data from LEP2 with the corresponding NLO predictions allow us to test the universality of the FFs predicted by the factorization theorem.