# Phenomenological NLO analysis of eta(c) production at the LHC in the collider and fixed-target modes

## TL;DR

This paper provides NLO predictions for eta(c) production at the LHC in collider and fixed-target modes, comparing with existing data and analyzing uncertainties to aid future experimental studies.

## Contribution

It offers new NLO theoretical predictions for eta(c) production at 13 TeV and fixed-target energies, including comprehensive uncertainty analysis and branching ratio discussions.

## Key findings

- Good agreement between LHCb data and NLO predictions at 7 and 8 TeV.
- Predictions made for 13 TeV LHCb and 115 GeV fixed-target mode.
- Uncertainty analysis enhances the reliability of theoretical estimates.

## Abstract

In view of the good agreement between the LHCb prompt-eta(c) data at sqrt(s)=7 and 8 TeV and the NLO colour-singlet model predictions --i.e. the leading v^2 NRQCD contribution--, we provide predictions in the LHCb acceptance for the forthcoming 13 TeV analysis bearing on data taken during the LHC Run2. We also provide predictions for sqrt(s)=115 GeV for proton-hydrogen collisions in the fixed-target mode which could be studied during the LHC Run3. Our predictions are complemented by a full theoretical uncertainty analysis. In addition to cross section predictions, we elaborate on the uncertainties on the p bar-p branching ratio --necessary for data-theory comparison-- and discuss other usable branching fractions for future studies.