Single inclusive pion pT-spectra in proton-proton collisions at sqrt(s) = 22.4GeV: data versus perturbative QCD calculations

TL;DR

This paper compares experimental pion transverse momentum spectra in proton-proton collisions at around 22 GeV with NLO pQCD calculations, providing a parametrization of the baseline spectrum for future nucleus-nucleus collision studies.

Contribution

It offers a detailed comparison between experimental data and NLO pQCD predictions at intermediate energies and proposes a practical parametrization of the p-p baseline spectrum.

Findings

NLO pQCD reproduces the experimental spectra in magnitude and shape.

Theoretical scale dependence is significant but manageable.

Provides a parametrization for baseline p-p spectra at 22.4 GeV.

Abstract

We compare the inclusive transverse momentum spectra of single pions above pT = 3 GeV/c measured in proton-proton (p-p) collisions at sqrt(s) = 21.7 - 23.8 GeV, with next-to-leading order (NLO) perturbative QCD (pQCD) predictions using recent parametrizations of the parton densities and parton-to-pion fragmentation functions. Although the dependence on the theoretical scales is large, the calculations can reproduce the experimental results both in magnitude and shape. Based on the existing data and on a pQCD $\sqrt{s}$-rescaling of the measured spectra, we provide a practical parametrization of the baseline p-p pion transverse momentum spectrum to be compared to nucleus-nucleus collisions data at sqrt(s_NN) = 22.4 GeV.