QCD factorization for hadronic quarkonium production at high $p_T$

TL;DR

This paper applies QCD factorization to analyze heavy quarkonium production at high transverse momentum, demonstrating its effectiveness in describing the $p_T$ spectrum of $J/\psi$ at the LHC through numerical analysis of fragmentation functions.

Contribution

It introduces a numerical analysis of the scale evolution of twist-2 and twist-4 fragmentation functions for heavy quarkonium, extending QCD factorization to low and high $p_T$ regions.

Findings

QCD factorization describes $p_T$ spectrum of $J/\psi$ at LHC

Leading power dominates high $p_T$, next-to-leading power is needed at low $p_T$

First numerical analysis of coupled twist-2 and twist-4 FFs

Abstract

Heavy quarkonium production at high transverse momentum ($p_T$) in hadronic collisions is explored in the QCD factorization approach. We find that the leading power in the $1/p_T$ expansion is responsible for high $p_T$ regime, while the next-to-leading power contribution is necessary for the low $p_T$ region. We present the first numerical analysis of the scale evolution of coupled twist-2 and twist-4 fragmentation functions (FFs) for heavy quarkonium production and demonstrate that the QCD factorization approach is capable of describing the $p_T$ spectrum of hadronic $J/\psi$ production at the LHC.