# Predictions for the isolated prompt photon production at the LHC at $ \sqrt s= $13 TeV

## TL;DR

This paper provides theoretical predictions for isolated prompt photon production at 13 TeV proton-proton collisions at the LHC, analyzing the impact of different parton distribution functions and scale uncertainties.

## Contribution

It offers detailed predictions for prompt photon production using modern PDFs and studies the effects of scale variations and PDF choices on the results.

## Key findings

- Predictions cover photon transverse energy and pseudorapidity distributions.
- Theoretical uncertainties are quantified through scale variation analysis.
- Ratios of photon momenta across rapidity regions are calculated and analyzed.

## Abstract

The prompt photon production in hadronic collisions has a long history of providing information on the substructure of hadrons and testing the perturbative techniques of QCD. Some valuable information about the parton densities in the nucleon and nuclei, especially of the gluon, can also be achieved by analysing the measurements of the prompt photon production cross section whether inclusively or in association with heavy quarks or jets. In this work, we present predictions for the inclusive isolated prompt photon production in $ pp $ collisions at center-of-mass energy of 13 TeV using various modern PDF sets. The calculations are presented both as a function of photon transverse energy $ E_\textrm{T}^\gamma $ and pseudorapidity $ \eta^\gamma $ for the ATLAS kinematic coverage. We also study in detail the theoretical uncertainty in the cross sections due to the variation of the renormalization, factorization and fragmentation scales. Moreover, we introduce and calculate the ratios of photon momenta for different rapidity regions and study the impact of various input PDFs on such quantity.