  Soft-drop grooming of hadron-collision final states has the potential to
significantly reduce the impact of non-perturbative corrections, and in
particular the underlying-event contribution. This eventually will enable a
more direct comparison of accurate perturbative predictions with experimental
measurements. In this study we consider soft-drop groomed dijet event shapes.
We derive general results needed to perform the resummation of suitable
event-shape variables to next-to-leading logarithmic (NLL) accuracy matched to
exact next-to-leading order (NLO) QCD matrix elements. We compile predictions
for the transverse-thrust shape accurate to NLO+NLL' using the implementation
of the CAESAR formalism in the Sherpa event generator framework. We complement
this by state-of-the-art parton- and hadron-level predictions based on NLO QCD
matrix elements matched with parton showers. We explore the potential to
mitigate non-perturbative corrections for particle-level and track-based
measurements of transverse thrust by considering a wide range of soft-drop
parameters. We find that soft-drop grooming indeed is very efficient in
removing the underlying event. This motivates future experimental measurements
to be compared to precise QCD predictions and employed to constrain
non-perturbative models in Monte-Carlo simulations.
