Global analysis of $\psi(2S)$ inclusive hadroproduction at next-to-leading order in nonrelativistic-QCD factorization

TL;DR

This paper performs a detailed next-to-leading order analysis of $(2S)$ meson production in high-energy collisions, fitting nonperturbative parameters with extensive data to improve precision in quantum chromodynamics predictions.

Contribution

It provides the first high-precision determination of color octet long-distance matrix elements for $(2S)$ within the nonrelativistic-QCD framework at NLO, using a large dataset.

Findings

Successful data description requires a low transverse momentum cut.

Results are an order of magnitude more precise than previous estimates.

Different polarization and $p_T$ cuts influence the fit quality.

Abstract

Working in the nonrelativistic-QCD factorization framework at next-to-leading order in $\alpha_s$, we fit the relevant color octet (CO) long-distance matrix elements (LDMEs) of the $\psi(2S)$ meson, $\langle {\cal O}^{\psi(2S)}({^1S}_0^{[8]})\rangle$, $\langle {\cal O}^{\psi(2S)}({^3S}_1^{[8]})\rangle$, and $\langle {\cal O}^{\psi(2S)}({^3P}_0^{[8]})\rangle$, to 1001 data points of upolarized and polarized $\psi(2S)$ inclusive hadroproduction. We do four different fits, with filters on polarization and low to middle transverse momentum $p_T$. We find that a successful description of the data is only possible with a large low-$p_T$ cut. Our results are one order of magnitude more precise than previous determinations of these color octet long-distance matrix elements.