Hadron Production in Hadron-Hadron and Lepton-Hadron Collisions

Abstract

We review a recent global analysis of inclusive single-charged-hadron production in high-energy colliding-beam experiments, which is performed at next-to-leading order (NLO) in the parton model of quantum chromodynamics endowed with nonperturbative fragmentation functions (FFs). Comparisons of p p-bar data from CERN S p p-bar S and the Fermilab Tevatron and gamma p data from DESY HERA with the corresponding NLO predictions allow for quantitative tests of the scaling violations in the FFs and their universality. We emphasize the potential of new measurements at the Tevatron to place tight constraints in the large-x region and on the gluon FF, complementary to those from e^+ e^- data, which are indispensible in order to reliably predict the pi^0 background for the H -> gamma gamma signal of the intermediate-mass Higgs boson at the Tevatron and the CERN LHC. Adopting a similar theoretical framework for b-hadron production, we show that the notorious excess of the Tevatron data over existing theoretical calculations can be ascribed, at sufficiently large values of p_T, to nonperturbative fragmentation effects inadequately included previously.