# Measurement of forward photon production cross-section in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the LHCf detector

## TL;DR

This paper measures the forward photon production cross-section in proton-proton collisions at 13 TeV using the LHCf detector, providing data to test and improve hadronic interaction models for cosmic ray simulations.

## Contribution

First measurement of forward photon production cross-section at 13 TeV in specific pseudorapidity regions using LHCf data, comparing results with hadronic models.

## Key findings

- EPOS-LHC best matches the experimental data
- None of the models perfectly agree with measurements
- Provides crucial data for cosmic ray air-shower model validation

## Abstract

In this paper, we report the production cross-section of forward photons in the pseudorapidity regions of $\eta\,>\,10.94$ and $8.99\,>\,\eta\,>\,8.81$, measured by the LHCf experiment with proton--proton collisions at $\sqrt{s}$ = 13 TeV. The results from the analysis of 0.191 $\mathrm{nb^{-1}}$ of data obtained in June 2015 are compared to the predictions of several hadronic interaction models that are used in air-shower simulations for ultra-high-energy cosmic rays. Although none of the models agree perfectly with the data, EPOS-LHC shows the best agreement with the experimental data among the models.