Impact of relativistic corrections to high-pT prompt-psi(2S) production at hadron colliders

Abstract

We study relativistic corrections to prompt psi(2S) at high pT in hadron colliders. Our calculation employs leading-power factorization with Fragmentation Functions (FFs) computed in nonrelativistic QCD and evolved to next-to-leading-logarithmic accuracy. Relativistic corrections increase the cross section significantly for the gluon channel, but moderately for charm. We perform a full analysis of uncertainties. We observe a good agreement with both ATLAS and CMS cross sections without the need of higher-order color-octet contributions. The polar anisotropy is found to be close to CMS data.

Figures (2)

• Figure 1: (a) Prompt ATLAS and CMS $\psi(2S\!)\xspace$$P_T$-differential cross sections ATLAS:2023qnhCMS:2017dju at $\sqrt{s} = 13~\text{TeV}$ compared to our results for coupled $c$ & $g$ (hatched red), $c$ (solid green), and $g$ (solid gray-blue) channels. (b) Prompt $\psi(2S\!)\xspace$ polar anisotropy $\lambda_\theta$ from CMS CMS:2024igk, compared to our coupled $c$ & $g$ results. Solid and dashed curves show different scale choices and red curves show the combined scale and PDF uncertainty. (c) Same as (b) but for the cross section ratio to ATLAS data. We use $|R(0)|^2 = 0.53~(0.93)~\text{GeV}^3$ and $\langle v^2 \rangle = 0.50~(0.25)$ for upper (lower) panels.
• Figure 2: FCC-hh predictions for prompt $\psi(2S\!)\xspace$ production at $\sqrt{s}=100$ TeV and $|y|<2.5$. Same curves as Fig. \ref{['fig:Atlas']} along with that for coupled evolution without $v^2$ corrections (orange hatched).