  We study hadronic jets that are tagged as heavy-flavoured, i.e. they contain
either beauty or charm. In particular, we consider heavy-flavour jets that have
been groomed with the Soft Drop algorithm. In order to achieve a deeper
understanding of these objects, we apply resummed perturbation theory to jets
initiated by a massive quark and we perform analytic calculations for two
variables that characterise Soft Drop jets, namely the opening angle and the
momentum fraction of the splitting that passes Soft Drop. We compare our
findings to Monte Carlo simulations. Furthermore, we investigate the
correlation between the Soft Drop energy fraction and alternative observables
that aim to probe heavy-quark fragmentation functions.
