Inclusive Hadron Production in the CERN-LHC Era
M. Stratmann, R. Sassot, P. Zurita
TL;DR
The paper tackles inclusive hadron production at LHC energies within the QCD factorization framework, formulating the observable cross section with $pp$ and $pPb$ collisions and aiming to constrain hadronization via fragmentation functions across a wide $p_T$ range. It employs next-to-leading order QCD with modern vacuum FFs and extends to nuclear environments through medium-modified FFs and nPDFs, enabling predictions for pion production in $pPb$ collisions. A key methodological contribution is the use of the Lagrange multiplier technique to propagate FF uncertainties to observables and to study scale and PDF dependencies, providing a robust uncertainty analysis. The study generates predictions for energies from $900$ GeV up to $14$ TeV and discusses how early LHC data can refine FFs and illuminate hadronization in nuclear matter, highlighting where perturbative predictions hold and where non-perturbative effects become important.
Abstract
We present a detailed phenomenological analysis of single-inclusive hadron production at the CERN-LHC in both proton-proton and proton-lead collisions. First data from the LHC experiments on charged hadron spectra are compared to next-to-leading order QCD expectations, and predictions are made for identified pion, kaon, and proton distributions differential in transverse momentum and rapidity for LHC energies from 900 GeV to 14 TeV. The results are obtained with the latest sets of vacuum fragmentation functions based on global QCD analyses, and recently proposed medium modified fragmentation functions are used to model hadronization in proton-lead collisions assuming standard QCD factorization. Besides estimating theoretical ambiguities due to the choice of factorization and renormalization scales and parton densities, we carefully assess uncertainties due to our present knowledge of parton-to-hadron fragmentation functions with the Lagrange multiplier technique. It is outlined to what extent future LHC data will contribute to further our quantitative understanding of hadronization processes.