  Recent measurements at the LHC have revealed heavy-flavour baryon fractions
much larger than those observed at LEP, with e.g., LambdaC+/D0 and LambdaB0/B0
reaching ~ 0.5 at low pT. One scenario that has been at least partly successful
in predicting observed trends is QCD colour reconnections with string
junctions. In previous work, however, the limit of a low-pT heavy quark was not
well defined. We reconsider the string equations of motion for junction systems
in this limit, and find that the junction effectively becomes bound to the
heavy quark, a scenario we refer to as a "pearl on a string". We extend
string-junction fragmentation in Pythia with a dedicated modelling of this
limit for both light- and heavy-quark "pearls".
