Recent measurements dedicated to improving the understanding of modelling top quark pair (${ \text{ t}\overline{ \text{ t}}}$) production at the LHC are summarised. These measurements, performed with proton-proton collision data collected by the CMS detector at $\sqrt{ s}=$ 13 TeV, probe the underlying event in ${ \text{ t}\overline{ \text{ t}}}$ events, and use the abundance of jets in ${ \text{ t}\overline{ \text{ t}}}$ events to study the substructure of jets. A new set of tunes for PYTHIA 8, and their performance with ${ \text{ t}\overline{ \text{ t}}}$ data, are also discussed.
Categories: hep-ex