# Isolated photon and photon+jet production at NNLO QCD accuracy

## TL;DR

This paper presents NNLO QCD calculations for isolated photon and photon-plus-jet production, significantly reducing theoretical uncertainties and improving agreement with experimental data from ATLAS and CMS.

## Contribution

It provides the first NNLO QCD predictions for isolated photon and photon+jet production, incorporating experimental isolation criteria at the parton level.

## Key findings

- NNLO corrections reduce theory uncertainty to below 5%
- Enhanced agreement with ATLAS and CMS measurements
- Improved theoretical description of photon production processes

## Abstract

We describe the calculation of the next-to-next-to-leading order (NNLO) QCD corrections to isolated photon and photon-plus-jet production, and discuss how the experimental hadron-level photon definition and isolation criteria can be approximated in the theoretical parton-level calculation. The NNLO corrections lead to a considerable reduction of the theory uncertainty on the predictions, typically to less than five per cent, and enable an improved description of experimental measurements from ATLAS and CMS.