Inclusive charmonium production at PANDA experiment

TL;DR

This paper investigates inclusive charmonium production near threshold energies at the PANDA experiment, providing NLO calculations that explain experimental observations and emphasizing the importance of scale parameter choices.

Contribution

It offers a next-to-leading order analysis of charmonium production near threshold, explaining the presence of $ ext{chi}_{c1}$ mesons and highlighting the significance of scale parameter selection.

Findings

NLO calculations produce non-zero transverse momentum distributions.

The existence of $ ext{chi}_{c1}$ mesons is naturally explained.

Correct scale parameter choice is crucial for accurate predictions.

Abstract

The production of the charmonium states in proton-antiproton experiments is considered at the energy rates near threshold in NLO. Such a consideration allows one to obtain non zero distributions over the transverse momentum of the final charmonium and gives a natural explanation to the existence of $\chi_{c1}$-meson in final state, that is observed experimentally and cannot be produced in leading order processes. The crucial role of scale parameter choice in $\alpha_s (Q^2)$ and partonic distributions $f(x,Q^2)$ shown, and the correct choice offered.