# Top-pair production at the LHC through NNLO QCD and NLO EW

## TL;DR

This paper provides the first NNLO QCD and NLO EW predictions for top-quark pair differential distributions at the LHC, including photon PDF effects and correction combination methods, with negligible heavy boson radiation impact.

## Contribution

It introduces comprehensive NNLO QCD and NLO EW calculations for top-pair production, including higher-order EW terms and analysis of correction combination methods.

## Key findings

- Photon PDF significantly affects top $p_T$ spectra depending on the PDF set.
- Small differences between additive and multiplicative correction approaches.
- Heavy boson radiation has negligible effect on inclusive spectra.

## Abstract

In this work we present for the first time predictions for top-quark pair differential distributions at the LHC at NNLO QCD accuracy and including EW corrections. For the latter we include not only contributions of ${\cal O}(\alpha_s^2 \alpha)$, but also those of order ${\cal O}(\alpha_s \alpha^2)$ and ${\cal O}( \alpha^3)$. Besides providing phenomenological predictions for all main differential distributions with stable top quarks, we also study the following issues. 1) The effect of the photon PDF on top-pair spectra: we find it to be strongly dependent on the PDF set used -- especially for the top $p_T$ distribution. 2) The difference between the additive and multiplicative approaches for combining QCD and EW corrections: with our scale choice, we find relatively small differences between the central predictions, but reduced scale dependence within the multiplicative approach. 3) The potential effect from the radiation of heavy bosons on inclusive top-pair spectra: we find it to be, typically, negligible.