Jet Substructure at HERA
  Measurements of jet shapes and subjet multiplicities in photoproduction performed by ZEUS are presented and compared to leading-logarithm parton-shower Monte Carlo models. The predicted differences on the size of gluon- and quark-initiated jets are used to select samples to study the dynamics of the subprocesses. 
Claudia Glasman (University of Glasgow, representing the ZEUS   Collaboration)