Global analysis of the experimental data on $\chi_c$ meson hadroproduction

TL;DR

This paper performs a comprehensive analysis of experimental data on $$ meson production at high-energy colliders, updating theoretical parameters and demonstrating NLO QCD predictions align well with observed results.

Contribution

It provides a global fit of LDMEs at LO and NLO, showing NLO predictions match experimental data across various conditions, unlike LO.

Findings

NLO predictions agree with all experimental data sets.

LO predictions cannot fit all data with a single LDME value.

The scale dependence can be absorbed into the LDMEs.

Abstract

We carry out a global analysis of the experimental data on the $\chi_c$ production cross section and the ratio $\sigma(\chi_{c2})/\sigma(\chi_{c1})$ at the LHC and the Tevatron. The related long-distance matrix elements (LDMEs) at both leading order (LO) and next-to-leading order (NLO) in the QCD coupling constant are renewed. We also present the transverse momentum distribution of the $\chi_c$ production cross section and the ratio $\sigma(\chi_{c2})/\sigma(\chi_{c1})$ for several experimental conditions and find that NLO predictions agree with all sets of experimental data. By contrast, at LO, one cannot explain all the data with a unique value of the color-octet LDME. A brief analysis of the nonrelativistic QCD scale dependence of the cross sections shows that, for the conditions we are concerned with in this paper, the dependence can be almost totally absorbed into the LDME.