Measurement of the differential cross-sections of prompt and non-prompt production of $J/\psi$ and $\psi(2\mathrm{S})$ in $pp$ collisions at $\sqrt{s} = 7$ and $8$ TeV with the ATLAS detector

TL;DR

This paper reports precise measurements of prompt and non-prompt $J/ar{psi}$ and $ar{ ext{psi}}(2S)$ production cross-sections in proton-proton collisions at 7 and 8 TeV, comparing results to theoretical models.

Contribution

It provides the first detailed double-differential cross-section measurements for both prompt and non-prompt charmonium states at these energies, with comprehensive data correction and comparison.

Findings

Measured production cross-sections as functions of $p_T$ and rapidity.

Quantified ratios of $ar{ ext{psi}}(2S)$ to $J/ar{psi}$ production.

Determined fractions of non-prompt production in the dataset.

Abstract

The production rates of prompt and non-prompt $J/\psi$ and $\psi(2\mathrm{S})$ mesons are measured using 2.1 $fb^{-1}$ and 11.4 $fb^{-1}$ of data collected with the ATLAS experiment at the LHC, in proton-proton collisions at $\sqrt{s}=7$ and 8 TeV respectively. Production cross-sections for both prompt and non-prompt production sources, ratios of $\psi(2\mathrm{S})$ to $J/\psi$ production, and fractions of non-prompt to inclusive production for $J/\psi$ and $\psi(2\mathrm{S})$ are measured double-differentially as a function of meson $p_{T}$ and rapidity. These measurements are made in a restricted fiducial volume and also corrected for geometrical acceptance after which they are compared to a variety of theoretical predictions.