In this talk, we introduce a new jet substructure method based on a
recursive iteration of the Soft Drop algorithm through both branches
of the clustering tree.
Recursive soft drop uses an additional parameter N to define the
number of layers of soft drop declustering, providing an optimized
grooming strategy for boosted objects with (N+1)-prong decays, as well
as improved stability in high pileup conditions. We discuss the
infinite N limit, where groomed jets have a null area, and investigate
the robustness of recursive soft drop to non-perturbative effects.
We show promising applications to jet mass resolution in boosted top
and W bosons, and demonstrate how recursive soft drop grooming can
improve pileup mitigation when used in conjunction with existing