Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The impact of the photon PDF and electroweak corrections on $t \bar t$
  distributions   We discuss the impact of EW corrections on differential distributions in
top-quark pair production at the LHC and future hadron colliders, focusing on
the effects of initial-state photons. Performing a calculation at
Next-to-Leading Order QCD+EW accuracy, we investigate in detail the impact of
photon-initiated channels on central values as well as PDF and scale
uncertainties, both at order $\alpha_s\alpha$ and $\alpha_s^2\alpha$. We
present predictions at 13 and 100 TeV, and provide results for the 8 TeV
differential measurements performed by ATLAS and CMS. A thorough comparison of
results obtained with the NNPDF2.3QED and CT14QED PDF sets is performed. While
contributions due to the photon PDF are negligible with CT14QED, this is not
the case for NNPDF2.3QED, where such contributions are sizeable and show large
PDF uncertainties. On the one hand, we show that differential observables in
top-pair production, in particular top-quark and $t\bar t$ rapidities, can be
used to improve the determination of the photon PDF within the NNPDF approach.
On the other hand, with current PDF sets, we demonstrate the necessity of
including EW corrections and photon-induced contributions for a correct
determination of both the central value and the uncertainties of theoretical
predictions.

17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas