Single-inclusive production of large-pT charged particles in hadronic collisions at TeV energies and perturbative QCD predictions

TL;DR

This paper compares Tevatron charged particle data with NLO QCD predictions, finds significant discrepancies at high pT, and provides predictions and methods for LHC energies, highlighting potential issues in experimental data and offering tools for future analyses.

Contribution

It presents a detailed comparison of Tevatron data with NLO QCD predictions and proposes methods to estimate charged hadron spectra at LHC energies.

Findings

Significant disagreement between Tevatron data and NLO predictions above pT~20 GeV/c.

Predictions for charged hadron spectra at LHC energies with theoretical uncertainties.

Two procedures proposed for estimating spectra at heavy-ion collision energies from p-p data.

Abstract

The single inclusive spectrum of charged particles with transverse momenta pT=3-150 GeV/c measured at midrapidity by the CDF experiment in proton-antiproton (p-pbar) collisions at sqrt(s)=1.96 TeV is compared to next-to-leading order (NLO) perturbative QCD calculations using the most recent parametrizations of the parton distributions and parton-to-hadron fragmentation functions. Above pT~20 GeV/c, there is a very sizeable disagreement of the Tevatron data compared to the NLO predictions and to xT-scaling expectations, suggesting a problem in the experimental data. We also present the predictions for the pT-differential charged hadron spectra and the associated theoretical uncertainties for proton-proton (p-p) collisions at LHC energies (sqrt(s)=0.9-14 TeV). Two procedures to estimate the charged hadron spectra at LHC heavy-ion collision energies (sqrt(s)=2.76,5.5 TeV) from p-p measurements are suggested.