# MMHT PDFs: updates and outlook

## TL;DR

This paper updates the MMHT parton distribution functions with new LHC data, examines the impact of systematic uncertainties and NNLO corrections, and discusses the inclusion of the photon PDF, highlighting improvements and challenges in fitting collider data.

## Contribution

It introduces recent updates to the MMHT PDFs, analyzes the effects of systematic uncertainties and higher-order corrections, and explores the integration of photon PDFs into the framework.

## Key findings

- Improved fit to ATLAS jet data by decorrelating systematic uncertainties.
- Inclusion of new LHC data reduces the strange quark PDF uncertainty.
- NNLO corrections mildly decrease the overall fit quality.

## Abstract

We present the latest results of studies within the MMHT PDF framework. We discuss the impact of the most recent ATLAS 7 TeV jet data, demonstrating that while a good fit can be achieved for individual jet rapidity bins, it is not possible to achieve a good description of the data when all bins are fitted. We examine the role that the experimental correlated systematic uncertainties play in this, and demonstrate that by simply decorrelating no more than two sources of error between rapidity bins a remarkably improved description of the data can be achieved. We then study the impact of NNLO corrections, showing that a mild decrease in the fit quality is produced. We also present the results of including new LHC $W$, $Z$, $W+c$ and $t\overline{t}$ data on the MMHT14 PDF set, showing that a marked decrease in the $s+\overline{s}$ uncertainty is in particular achieved. Finally, some discussion of the latest work towards the inclusion of the photon PDF within the MMHT framework is presented.