Subjet distributions in deep inelastic scattering at HERA 

                 ZEUS Collaboration

Subjet distributions were measured in neutral current deep inelastic ep 
scattering with the ZEUS detector at HERA using an integrated luminosity 
of 81.7 pb-1. Jets were identified using the kT cluster algorithm in the 
laboratory frame. Subjets were defined as jet-like substructures identified 
by a reapplication of the cluster algorithm at a smaller value of the 
resolution parameter ycut. Measurements of subjet distributions for jets 
with exactly two subjets for ycut=0.05 are presented as functions of 
observables sensitive to the pattern of parton radiation and to the colour 
coherence between the initial and final states. Perturbative QCD predictions 
give an adequate description of the data.